diff --git a/.gitignore b/.gitignore
index 12d89e61..c2d85744 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 /node_modules
 /dist
+.tsbuildinfo
 /dump
 .env
 .env.test
diff --git a/scripts/chatContentUserIdUpdater.js b/scripts/chatContentUserIdUpdater.js
new file mode 100644
index 00000000..0063542a
--- /dev/null
+++ b/scripts/chatContentUserIdUpdater.js
@@ -0,0 +1,41 @@
+const { MongoClient } = require("mongodb");
+const { mongo: mongoUrl } = require("@/loadenv");
+
+const client = new MongoClient(mongoUrl);
+const db = client.db("taxi");
+const chats = db.collection("chats");
+const users = db.collection("users");
+
+async function convertUserIdToOid(userId) {
+  const user = await users.findOne({ id: userId, withdraw: false }, "_id");
+  if (!user) throw new Error(`User not found: ${userId}`);
+  return user._id.toString();
+}
+
+async function run() {
+  try {
+    for await (const doc of chats.find()) {
+      if (doc.type === "in" || doc.type === "out") {
+        const inOutUserIds = doc.content.split("|");
+        const inOutUserOids = await Promise.all(
+          inOutUserIds.map(convertUserIdToOid)
+        );
+        await chats.updateOne(
+          { _id: doc._id },
+          { $set: { content: inOutUserOids.join("|") } }
+        );
+      } else if (doc.type === "payment" || doc.type === "settlement") {
+        const userId = doc.content;
+        const userOid = await convertUserIdToOid(userId);
+        await chats.updateOne({ _id: doc._id }, { $set: { content: userOid } });
+      }
+    }
+  } catch (err) {
+    console.error(err);
+  } finally {
+    await client.close();
+  }
+}
+run().then(() => {
+  console.log("Done!");
+});
diff --git a/src/lottery/services/globalState.js b/src/lottery/services/globalState.js
index ee01f47e..7a16d0e7 100644
--- a/src/lottery/services/globalState.js
+++ b/src/lottery/services/globalState.js
@@ -95,7 +95,7 @@ const createUserGlobalStateHandler = async (req, res) => {
         error: "GlobalState/create : invalid inviter",
       });
 
-    const user = await userModel.findById(req.userOid);
+    const user = await userModel.findOne({ _id: req.userOid, withdraw: false });
     if (!user)
       return res
         .status(500)
diff --git a/src/lottery/services/invites.js b/src/lottery/services/invites.js
index 6479bce8..935e158e 100644
--- a/src/lottery/services/invites.js
+++ b/src/lottery/services/invites.js
@@ -24,7 +24,10 @@ const searchInviterHandler = async (req, res) => {
 
     // 해당되는 유저의 닉네임과 프로필 이미지를 가져옵니다.
     const inviter = await userModel
-      .findById(inviterStatus.userId, "nickname profileImageUrl")
+      .findOne(
+        { _id: inviterStatus.userId, withdraw: false },
+        "nickname profileImageUrl"
+      )
       .lean();
     if (!inviter)
       return res
diff --git a/src/lottery/services/items.js b/src/lottery/services/items.js
index 07730574..c5f5a2c5 100644
--- a/src/lottery/services/items.js
+++ b/src/lottery/services/items.js
@@ -125,7 +125,13 @@ const getItemLeaderboardHandler = async (req, res) => {
       leaderboardBase
         .filter((user) => user.rank <= 20)
         .map(async (user) => {
-          const userInfo = await userModel.findById(user.userId).lean();
+          const userInfo = await userModel
+            .findOne({ _id: user.userId, withdraw: false })
+            .lean();
+          if (!userInfo) {
+            logger.error(`Fail to find user ${user.userId}`);
+            return null;
+          }
           return {
             nickname: userInfo.nickname,
             profileImageUrl: userInfo.profileImageUrl,
@@ -135,6 +141,10 @@ const getItemLeaderboardHandler = async (req, res) => {
           };
         })
     );
+    if (leaderboard.includes(null))
+      return res
+        .status(500)
+        .json({ error: "Items/leaderboard : internal server error" });
 
     const userId = isLogin(req) ? getLoginInfo(req).oid : null;
     const user = leaderboardBase.find(
diff --git a/src/lottery/services/publicNotice.js b/src/lottery/services/publicNotice.js
index dd3dc91b..f0244421 100644
--- a/src/lottery/services/publicNotice.js
+++ b/src/lottery/services/publicNotice.js
@@ -41,7 +41,7 @@ const getRecentPurchaceItemListHandler = async (req, res) => {
         .find({ type: "use", itemType: 0 })
         .sort({ createAt: -1 })
         .limit(1000)
-        .populate(publicNoticePopulateOption)
+        .populate(publicNoticePopulateOption) // TODO: 회원 탈퇴 핸들링
         .lean()
     )
       .sort(
@@ -132,7 +132,10 @@ const getTicketLeaderboardHandler = async (req, res) => {
       );
     const leaderboard = await Promise.all(
       sortedUsers.slice(0, 20).map(async (user) => {
-        const userInfo = await userModel.findOne({ _id: user.userId }).lean();
+        // 여기서 userId는 oid입니다.
+        const userInfo = await userModel
+          .findOne({ _id: user.userId, withdraw: false })
+          .lean();
         if (!userInfo) {
           logger.error(`Fail to find user ${user.userId}`);
           return null;
@@ -211,7 +214,9 @@ const getGroupLeaderboardHandler = async (req, res) => {
         if (mvp?.length !== 1)
           throw new Error(`Fail to find MVP in group ${group.group}`);
 
-        const mvpInfo = await userModel.findOne({ _id: mvp[0].userId }).lean();
+        const mvpInfo = await userModel
+          .findOne({ _id: mvp[0].userId, withdraw: false })
+          .lean();
         if (!mvpInfo) throw new Error(`Fail to find user ${mvp[0].userId}`);
 
         return {
diff --git a/src/middlewares/auth.ts b/src/middlewares/auth.ts
index a0215b9d..c9f6c0d7 100644
--- a/src/middlewares/auth.ts
+++ b/src/middlewares/auth.ts
@@ -8,9 +8,9 @@ const authMiddleware: RequestHandler = (req, res, next) => {
       error: "not logged in",
     });
 
-  const { id, oid } = getLoginInfo(req);
-  req.userId = id;
+  const { oid } = getLoginInfo(req);
   req.userOid = oid;
+
   next();
 };
 
diff --git a/src/middlewares/authAdmin.ts b/src/middlewares/authAdmin.ts
index cc79ef29..5f323cc2 100644
--- a/src/middlewares/authAdmin.ts
+++ b/src/middlewares/authAdmin.ts
@@ -11,8 +11,8 @@ const authAdminMiddleware: RequestHandler = async (req, res, next) => {
     if (!isLogin(req)) return res.redirect(redirectUrl);
 
     // 관리자 유무를 확인
-    const { id } = getLoginInfo(req);
-    const user = await userModel.findOne({ id });
+    const { oid } = getLoginInfo(req);
+    const user = await userModel.findOne({ _id: oid, withdraw: false });
     if (!user?.isAdmin) return res.redirect(redirectUrl);
 
     // 접속한 IP가 화이트리스트에 있는지 확인
diff --git a/src/modules/auths/login.ts b/src/modules/auths/login.ts
index 962c260f..fe662503 100644
--- a/src/modules/auths/login.ts
+++ b/src/modules/auths/login.ts
@@ -1,6 +1,13 @@
 import type { Request } from "express";
-import { session as sessionConfig } from "@/loadenv";
+import { session as sessionConfig, sparcssso as sparcsssoEnv } from "@/loadenv";
 import logger from "@/modules/logger";
+import SsoClient from "./sparcssso";
+
+// 환경변수 SPARCSSSO_CLIENT_ID 유무에 따라 로그인 방식이 변경됩니다.
+export const isAuthReplace = !sparcsssoEnv.id;
+export const ssoClient = !isAuthReplace
+  ? new SsoClient(sparcsssoEnv.id, sparcsssoEnv.key)
+  : undefined;
 
 export interface LoginInfo {
   id: string;
diff --git a/src/modules/ban.ts b/src/modules/ban.ts
index f5276f23..bb62214a 100644
--- a/src/modules/ban.ts
+++ b/src/modules/ban.ts
@@ -32,7 +32,7 @@ export const validateServiceBanRecord = async (
       .toISOString()
       .replace("T", " ")
       .split(".")[0];
-    const banErrorMessage = `${req.originalUrl} : user ${req.userId} (${
+    const banErrorMessage = `${req.originalUrl} : user ${req.userOid} (${
       req.session.loginInfo!.sid
     }) is temporarily restricted from service until ${formattedExpireAt}.`;
     return banErrorMessage;
diff --git a/src/modules/fcm.ts b/src/modules/fcm.ts
index 50ee26db..9f80c4f3 100644
--- a/src/modules/fcm.ts
+++ b/src/modules/fcm.ts
@@ -93,6 +93,28 @@ export const unregisterDeviceToken = async (deviceToken: string) => {
   }
 };
 
+/**
+ * 사용자의 ObjectId가 주어졌을 때, 해당 사용자의 모든 deviceToken을 DB에서 삭제합니다.
+ * @param userId - 사용자의 ObjectId입니다.
+ * @return 해당 사용자로부터 deviceToken을 삭제하는 데 성공하면 true, 실패하면 false를 반환합니다. 삭제할 deviceToken이 존재하지 않는 경우에는 true를 반환합니다.
+ */
+export const unregisterAllDeviceTokens = async (userId: string) => {
+  try {
+    // 사용자의 디바이스 토큰을 DB에서 가져옵니다.
+    // getTokensOfUsers 함수의 정의는 아래에 있습니다. (호이스팅)
+    const tokens = await getTokensOfUsers([userId]);
+
+    // 디바이스 토큰과 관련 설정을 DB에서 삭제합니다.
+    await deviceTokenModel.deleteMany({ userId });
+    await notificationOptionModel.deleteMany({ deviceToken: { $in: tokens } });
+
+    return true;
+  } catch (error) {
+    logger.error(error);
+    return false;
+  }
+};
+
 /**
  * 메시지 전송에 실패한 deviceToken을 DB에서 삭제합니다.
  * @param deviceTokens - 사용자의 ObjectId입니다.
diff --git a/src/modules/populates/chats.ts b/src/modules/populates/chats.ts
index 077f7dad..efb1b392 100644
--- a/src/modules/populates/chats.ts
+++ b/src/modules/populates/chats.ts
@@ -4,9 +4,15 @@ import type { User, Chat } from "@/types/mongo";
  * 쿼리를 통해 얻은 Chat Document를 populate할 설정값을 정의합니다.
  */
 export const chatPopulateOption = [
-  { path: "authorId", select: "_id nickname profileImageUrl" },
+  {
+    path: "authorId",
+    select: "_id nickname profileImageUrl withdraw",
+  },
 ];
 
 export interface PopulatedChat extends Omit<Chat, "authorId"> {
-  authorId?: Pick<User, "_id" | "nickname" | "profileImageUrl">;
+  authorId: Pick<
+    User,
+    "_id" | "nickname" | "profileImageUrl" | "withdraw"
+  > | null;
 }
diff --git a/src/modules/populates/reports.ts b/src/modules/populates/reports.ts
index 6fcf60f3..1d30a07e 100644
--- a/src/modules/populates/reports.ts
+++ b/src/modules/populates/reports.ts
@@ -3,13 +3,13 @@ import type { User, Report } from "@/types/mongo";
 export const reportPopulateOption = [
   {
     path: "reportedId",
-    select: "_id id name nickname profileImageUrl",
+    select: "_id id name nickname profileImageUrl withdraw",
   },
 ];
 
 export interface PopulatedReport extends Omit<Report, "reportedId"> {
   reportedId: Pick<
     User,
-    "_id" | "id" | "name" | "nickname" | "profileImageUrl"
-  >;
+    "_id" | "id" | "name" | "nickname" | "profileImageUrl" | "withdraw"
+  > | null;
 }
diff --git a/src/modules/populates/rooms.ts b/src/modules/populates/rooms.ts
index 6eb87461..25b0bfff 100644
--- a/src/modules/populates/rooms.ts
+++ b/src/modules/populates/rooms.ts
@@ -15,28 +15,47 @@ export const roomPopulateOption = [
   {
     path: "part",
     select: "-_id user settlementStatus readAt",
-    populate: { path: "user", select: "_id id name nickname profileImageUrl" },
+    populate: {
+      path: "user",
+      select: "_id id name nickname profileImageUrl withdraw",
+    },
   },
 ];
 
 interface PopulatedParticipant
   extends Pick<Participant, "settlementStatus" | "readAt"> {
-  user: Pick<User, "_id" | "id" | "name" | "nickname" | "profileImageUrl">;
+  user: Pick<
+    User,
+    "_id" | "id" | "name" | "nickname" | "profileImageUrl" | "withdraw"
+  > | null;
 }
 
 export interface PopulatedRoom extends Omit<Room, "from" | "to" | "part"> {
-  from: Pick<Location, "_id" | "koName" | "enName">;
-  to: Pick<Location, "_id" | "koName" | "enName">;
-  part?: PopulatedParticipant[];
+  from: Pick<Location, "_id" | "koName" | "enName"> | null;
+  to: Pick<Location, "_id" | "koName" | "enName"> | null;
+  part: PopulatedParticipant[];
 }
 
-export interface FormattedRoom
-  extends Omit<PopulatedRoom, "part" | "settlementTotal"> {
-  part?: {
+interface FormattedLocation {
+  _id: string;
+  enName: string;
+  koName: string;
+}
+
+export interface FormattedRoom {
+  _id: string;
+  name: string;
+  from: FormattedLocation;
+  to: FormattedLocation;
+  time: Date;
+  madeat: Date;
+  maxPartLength: number;
+  part: {
     _id: string;
     name: string;
     nickname: string;
     profileImageUrl: string;
+    withdraw: boolean;
     isSettlement?: SettlementStatus;
     readAt: Date;
   }[];
@@ -61,15 +80,27 @@ export const formatSettlement = (
 ): FormattedRoom => {
   return {
     ...roomObject,
-    part: roomObject.part?.map((participantSubDocument) => {
-      const { _id, name, nickname, profileImageUrl } =
-        participantSubDocument.user;
+    _id: roomObject._id!.toString(),
+    from: {
+      _id: roomObject.from!._id!.toString(),
+      enName: roomObject.from!.enName,
+      koName: roomObject.from!.koName,
+    },
+    to: {
+      _id: roomObject.to!._id!.toString(),
+      enName: roomObject.to!.enName,
+      koName: roomObject.to!.koName,
+    },
+    part: roomObject.part.map((participantSubDocument) => {
+      const { _id, name, nickname, profileImageUrl, withdraw } =
+        participantSubDocument.user!;
       const { settlementStatus, readAt } = participantSubDocument;
       return {
-        _id,
+        _id: _id!.toString(),
         name,
         nickname,
         profileImageUrl,
+        withdraw,
         isSettlement: includeSettlement ? settlementStatus : undefined,
         readAt: readAt ?? roomObject.madeat,
       };
@@ -81,15 +112,15 @@ export const formatSettlement = (
 };
 
 /**
- * roomPopulateOption을 사용해 populate된 Room Object와 사용자의 id(userId)가 주어졌을 때, 해당 사용자의 정산 상태를 반환합니다.
+ * roomPopulateOption을 사용해 populate된 Room Object와 사용자의 objectId가 주어졌을 때, 해당 사용자의 정산 상태를 반환합니다.
  * @param roomObject - roomPopulateOption을 사용해 populate된 변환한 Room Object입니다.
- * @param userId - 방 완료 상태를 확인하려는 사용자의 id(user.id)입니다.
+ * @param userOid - 방 완료 상태를 확인하려는 사용자의 objectId입니다.
  * @return 사용자의 해당 방에 대한 완료 여부(true | false)를 반환합니다. 사용자가 참여중인 방이 아닐 경우 undefined를 반환합니다.
  **/
-export const getIsOver = (roomObject: PopulatedRoom, userId: string) => {
+export const getIsOver = (roomObject: PopulatedRoom, userOid: string) => {
   // room document의 part subdoocument에서 사용자 id와 일치하는 정산 정보를 찾습니다.
   const participantSubDocuments = roomObject.part?.filter((part) => {
-    return part.user.id === userId;
+    return part.user?._id?.toString() === userOid;
   });
 
   // 방에 참여중이지 않은 사용자의 경우, undefined을 반환합니다.
diff --git a/src/modules/socket.js b/src/modules/socket.js
index 2e8fa12e..72c672fe 100644
--- a/src/modules/socket.js
+++ b/src/modules/socket.js
@@ -32,11 +32,11 @@ const transformChatsForRoom = async (chats) => {
     // inOutNames 배열(들어오거나 나간 사용자들의 닉네임으로 이루어진 배열)을 생성합니다.
     chat.inOutNames = [];
     if (chat.type === "in" || chat.type === "out") {
-      const inOutUserIds = chat.content.split("|");
+      const inOutUserOids = chat.content.split("|");
       chat.inOutNames = await Promise.all(
-        inOutUserIds.map(async (userId) => {
-          const user = await userModel.findOne({ id: userId }, "nickname");
-          return user.nickname;
+        inOutUserOids.map(async (userOid) => {
+          const user = await userModel.findById(userOid, "nickname");
+          return user?.nickname;
         })
       );
     }
@@ -46,6 +46,7 @@ const transformChatsForRoom = async (chats) => {
       authorId: chat.authorId?._id,
       authorName: chat.authorId?.nickname,
       authorProfileUrl: chat.authorId?.profileImageUrl,
+      authorIsWithdrew: chat.authorId?.withdraw,
       content: chat.content,
       time: chat.time,
       isValid: chat.isValid,
@@ -111,7 +112,7 @@ const getMessageBody = (type, nickname = "", content = "") => {
  * @param {Object} chat - 채팅 메시지 내용입니다.
  * @param {string} chat.roomId - 채팅 및 채팅 알림을 보낼 방의 ObjectId입니다.
  * @param {string} chat.type - 채팅 메시지의 유형입니다. "text" | "s3img" | "in" | "out" | "payment" | "settlement" | "account" | "departure" | "arrival" 입니다.
- * @param {string} chat.content - 채팅 메시지의 본문입니다. chat.type이 "s3img"인 경우에는 채팅의 objectId입니다. chat.type이 "in"이거나 "out"인 경우 입퇴장한 사용자의 id(!==ObjectId)입니다.
+ * @param {string} chat.content - 채팅 메시지의 본문입니다. chat.type이 "s3img"인 경우에는 채팅의 objectId입니다. chat.type이 "in"이거나 "out"인 경우 입퇴장한 사용자의 oid입니다.
  * @param {string} chat.authorId - optional. 채팅을 보낸 사용자의 ObjectId입니다.
  * @param {Date?} chat.time - optional. 채팅 메시지 전송 시각입니다.
  * @return {Promise<Boolean>} 채팅 및 알림 전송에 성공하면 true, 중간에 오류가 발생하면 false를 반환합니다.
@@ -136,7 +137,10 @@ const emitChatEvent = async (io, chat) => {
 
     // chat optionally contains authorId
     const { nickname, profileImageUrl } = authorId
-      ? await userModel.findById(authorId, "nickname profileImageUrl")
+      ? await userModel.findOne(
+          { _id: authorId, withdraw: false },
+          "nickname profileImageUrl"
+        )
       : {};
     if (authorId && (!nickname || !profileImageUrl)) {
       throw new IllegalArgumentsException();
@@ -163,9 +167,6 @@ const emitChatEvent = async (io, chat) => {
       .lean()
       .populate(chatPopulateOption);
 
-    chatDocument.authorName = nickname;
-    chatDocument.authorProfileUrl = profileImageUrl;
-
     const userIds = part.map((participant) => participant.user);
     const userIdsExceptAuthor = authorId
       ? part
diff --git a/src/modules/stores/mongo.ts b/src/modules/stores/mongo.ts
index 76924f2a..41ccfa3e 100755
--- a/src/modules/stores/mongo.ts
+++ b/src/modules/stores/mongo.ts
@@ -19,11 +19,12 @@ import type {
 const userSchema = new Schema<User>({
   name: { type: String, required: true }, //실명
   nickname: { type: String, required: true }, //닉네임
-  id: { type: String, required: true, unique: true }, //택시 서비스에서만 사용되는 id
+  id: { type: String, required: true }, //택시 서비스에서만 사용되는 id
   profileImageUrl: { type: String, required: true }, //백엔드에서의 프로필 이미지 경로
   ongoingRoom: [{ type: Schema.Types.ObjectId, ref: "Room" }], // 참여중인 진행중인 방 배열
   doneRoom: [{ type: Schema.Types.ObjectId, ref: "Room" }], // 참여중인 완료된 방 배열
-  withdraw: { type: Boolean, default: false },
+  withdraw: { type: Boolean, default: false }, //탈퇴 여부
+  withdrewAt: { type: Date }, //탈퇴 시각
   phoneNumber: { type: String }, // 전화번호 (2023FALL 이벤트부터 추가)
   ban: { type: Boolean, default: false }, //계정 정지 여부
   joinat: { type: Date, required: true }, //가입 시각
diff --git a/src/routes/auth.js b/src/routes/auth.js
index 534814f6..15fe76f0 100644
--- a/src/routes/auth.js
+++ b/src/routes/auth.js
@@ -6,10 +6,7 @@ const validator = require("@/middlewares/validator").default;
 const authHandlers = require("@/services/auth");
 const authReplaceHandlers = require("@/services/auth.replace");
 const mobileAuthHandlers = require("@/services/auth.mobile");
-
-// 환경변수 SPARCSSSO_CLIENT_ID 유무에 따라 로그인 방식이 변경됩니다.
-const { sparcssso: sparcsssoEnv } = require("@/loadenv");
-const isAuthReplace = !sparcsssoEnv?.id;
+const { isAuthReplace } = require("@/modules/auths/login");
 
 // 로그인 페이지로 redirect합니다.
 router.get(
diff --git a/src/routes/docs/users.js b/src/routes/docs/users.js
index f21c037a..f9a5c270 100644
--- a/src/routes/docs/users.js
+++ b/src/routes/docs/users.js
@@ -393,4 +393,43 @@ usersDocs[`${apiPrefix}/getBanRecord`] = {
   },
 };
 
+usersDocs[`${apiPrefix}/withdraw`] = {
+  post: {
+    tags: [tag],
+    summary: "회원 탈퇴",
+    description: "회원 탈퇴를 요청합니다.",
+    responses: {
+      200: {
+        content: {
+          "application/json": {
+            schema: {
+              type: "object",
+              properties: {
+                ssoLogoutUrl: {
+                  type: "string",
+                  description: "SSO 로그아웃 URL",
+                },
+              },
+            },
+          },
+        },
+      },
+      400: {
+        content: {
+          "text/html": {
+            example: "Users/withdraw : ongoing room exists",
+          },
+        },
+      },
+      500: {
+        content: {
+          "text/html": {
+            example: "Users/withdraw : internal server error",
+          },
+        },
+      },
+    },
+  },
+};
+
 module.exports = usersDocs;
diff --git a/src/routes/users.ts b/src/routes/users.ts
index 45514925..58d8addc 100755
--- a/src/routes/users.ts
+++ b/src/routes/users.ts
@@ -59,4 +59,7 @@ router.get("/resetProfileImg", userHandlers.resetProfileImgHandler);
 // 유저의 서비스 정지 기록들을 모두 반환합니다.
 router.get("/getBanRecord", userHandlers.getBanRecordHandler);
 
+// 회원 탈퇴를 요청합니다.
+router.post("/withdraw", validatorMiddleware, userHandlers.withdrawHandler);
+
 export default router;
diff --git a/src/sampleGenerator/src/testData.js b/src/sampleGenerator/src/testData.js
index 1209c52a..2866eafa 100644
--- a/src/sampleGenerator/src/testData.js
+++ b/src/sampleGenerator/src/testData.js
@@ -125,7 +125,7 @@ const generateJoinAbortChat = async (roomId, userOid, isJoining, time) => {
     roomId: roomId,
     type: isJoining ? "in" : "out",
     authorId: user._id,
-    content: user.id,
+    content: user._id,
     time: time,
     isValid: false,
   });
diff --git a/src/schedules/deleteUserInfo.js b/src/schedules/deleteUserInfo.js
new file mode 100644
index 00000000..0c7c5ce6
--- /dev/null
+++ b/src/schedules/deleteUserInfo.js
@@ -0,0 +1,42 @@
+const { userModel } = require("../modules/stores/mongo");
+const logger = require("../modules/logger");
+
+module.exports = async () => {
+  try {
+    // 탈퇴일로부터 5년 이상 경과한 사용자의 개인정보 삭제
+    await userModel.updateMany(
+      {
+        withdraw: true,
+        withdrewAt: {
+          $lte: new Date(Date.now() - 5 * 365 * 24 * 60 * 60 * 1000),
+        },
+        name: { $ne: "" },
+      },
+      {
+        $set: {
+          name: "",
+          nickname: "",
+          id: "",
+          profileImageUrl: "",
+          // ongoingRoom
+          // doneRoom
+          ban: false,
+          // joinat
+          agreeOnTermsOfService: false,
+          "subinfo.kaist": "",
+          "subinfo.sparcs": "",
+          "subinfo.facebook": "",
+          "subinfo.twitter": "",
+          email: "",
+          isAdmin: false,
+          account: "",
+        },
+        $unset: {
+          phoneNumber: "",
+        },
+      }
+    );
+  } catch (err) {
+    logger.error(err);
+  }
+};
diff --git a/src/schedules/index.ts b/src/schedules/index.ts
index ea1bb96f..473a0c6c 100644
--- a/src/schedules/index.ts
+++ b/src/schedules/index.ts
@@ -1,16 +1,20 @@
 import type { Express } from "express";
 import cron from "node-cron";
 import { naverMap } from "@/loadenv";
+
 import notifyBeforeDepart from "./notifyBeforeDepart";
 import notifyAfterArrival from "./notifyAfterArrival";
 import updateMajorTaxiFare from "./updateMajorTaxiFare";
 import updateMinorTaxiFare from "./updateMinorTaxiFare";
+import deleteUserInfo from "./deleteUserInfo";
 import autoSettlement from "./autoSettlement";
 
 const registerSchedules = (app: Express) => {
   cron.schedule("*/5 * * * *", notifyBeforeDepart(app));
   cron.schedule("*/10 * * * *", notifyAfterArrival(app));
+  cron.schedule("0 0 1 * *", deleteUserInfo);
   cron.schedule("1,11,21,31,41,51 * * * *", autoSettlement(app));
+
   if (naverMap.apiId && naverMap.apiKey) {
     cron.schedule("0,30 * * * * ", updateMajorTaxiFare(app));
     cron.schedule("0 18 * * *", updateMinorTaxiFare(app));
diff --git a/src/schedules/notifyAfterArrival.js b/src/schedules/notifyAfterArrival.js
index c2c01b25..31c0b354 100644
--- a/src/schedules/notifyAfterArrival.js
+++ b/src/schedules/notifyAfterArrival.js
@@ -1,5 +1,4 @@
 const { roomModel, chatModel } = require("@/modules/stores/mongo");
-// const { roomPopulateOption } = require("@/modules/populates/rooms");
 const { emitChatEvent } = require("@/modules/socket");
 const logger = require("@/modules/logger").default;
 
diff --git a/src/services/auth.js b/src/services/auth.js
index 2b9ba658..b6e15fd2 100644
--- a/src/services/auth.js
+++ b/src/services/auth.js
@@ -1,7 +1,12 @@
-const { sparcssso: sparcsssoEnv, nodeEnv, testAccounts } = require("@/loadenv");
+const { nodeEnv, testAccounts } = require("@/loadenv");
 const { userModel } = require("@/modules/stores/mongo");
 const { user: userPattern } = require("@/modules/patterns").default;
-const { getLoginInfo, logout, login } = require("@/modules/auths/login");
+const {
+  ssoClient,
+  getLoginInfo,
+  logout,
+  login,
+} = require("@/modules/auths/login");
 
 const { unregisterDeviceToken } = require("@/modules/fcm");
 const {
@@ -12,10 +17,6 @@ const {
 const jwt = require("@/modules/auths/jwt");
 const logger = require("@/modules/logger").default;
 
-// SPARCS SSO
-const Client = require("@/modules/auths/sparcssso");
-const client = new Client(sparcsssoEnv?.id, sparcsssoEnv?.key);
-
 const transUserData = (userData) => {
   const kaistInfo = userData.kaist_info ? JSON.parse(userData.kaist_info) : {};
 
@@ -36,8 +37,26 @@ const transUserData = (userData) => {
 };
 
 const joinus = async (req, userData) => {
+  const oldUser = await userModel
+    .findOne(
+      {
+        id: userData.id,
+        withdraw: true,
+      },
+      "withdrewAt"
+    )
+    .sort({ withdrewAt: -1 })
+    .lean();
+  if (oldUser && oldUser.withdrewAt) {
+    // 탈퇴 후 7일이 지나지 않았을 경우, 가입을 거부합니다.
+    const diff = req.timestamp - oldUser.withdrewAt.getTime();
+    if (diff < 7 * 24 * 60 * 60 * 1000) {
+      return false;
+    }
+  }
+
   const newUser = new userModel({
-    id: userData.id,
+    id: userData.id, // NOTE: SSO uid
     name: userData.name,
     nickname: generateNickname(userData.id),
     profileImageUrl: generateProfileImageUrl(),
@@ -51,6 +70,7 @@ const joinus = async (req, userData) => {
     email: userData.email,
   });
   await newUser.save();
+  return true;
 };
 
 const update = async (userData) => {
@@ -59,7 +79,7 @@ const update = async (userData) => {
     email: userData.email,
     "subinfo.kaist": userData.kaist,
   };
-  await userModel.updateOne({ id: userData.id }, updateInfo);
+  await userModel.updateOne({ id: userData.id, withdraw: false }, updateInfo); // NOTE: SSO uid 쓰는 곳
   logger.info(
     `Update user info: ${userData.id} ${userData.name} ${userData.email} ${userData.kaist}`
   );
@@ -68,12 +88,17 @@ const update = async (userData) => {
 const tryLogin = async (req, res, userData, redirectOrigin, redirectPath) => {
   try {
     const user = await userModel.findOne(
-      { id: userData.id },
+      { id: userData.id, withdraw: false }, // NOTE: SSO uid 쓰는 곳
       "_id name email subinfo id withdraw ban"
     );
     if (!user) {
-      await joinus(req, userData);
-      return tryLogin(req, res, userData, redirectOrigin, redirectPath);
+      if (await joinus(req, userData)) {
+        return tryLogin(req, res, userData, redirectOrigin, redirectPath);
+      } else {
+        const redirectUrl = new URL("/login/fail", redirectOrigin).href;
+        res.redirect(redirectUrl);
+        return;
+      }
     }
     if (
       user.name !== userData.name ||
@@ -113,7 +138,7 @@ const tryLogin = async (req, res, userData, redirectOrigin, redirectPath) => {
 const sparcsssoHandler = (req, res) => {
   const redirectPath = decodeURIComponent(req.query?.redirect || "%2F");
   const isApp = !!req.query.isApp;
-  const { url, state } = client.getLoginParams();
+  const { url, state } = ssoClient.getLoginParams();
 
   req.session.loginAfterState = {
     state: state,
@@ -143,7 +168,7 @@ const sparcsssoCallbackHandler = (req, res) => {
     return res.redirect(redirectUrl);
   }
 
-  client.getUserInfo(code).then((userDataBefore) => {
+  ssoClient.getUserInfo(code).then((userDataBefore) => {
     const userData = transUserData(userDataBefore);
     const isTestAccount = testAccounts?.includes(userData.email);
     if (userData.isEligible || nodeEnv !== "production" || isTestAccount) {
@@ -152,7 +177,7 @@ const sparcsssoCallbackHandler = (req, res) => {
       // 카이스트 구성원이 아닌 경우, SSO 로그아웃 이후, 로그인 실패 URI 로 이동합니다
       const { sid } = userData;
       const redirectUrl = new URL("/login/fail", redirectOrigin).href;
-      const ssoLogoutUrl = client.getLogoutUrl(sid, redirectUrl);
+      const ssoLogoutUrl = ssoClient.getLogoutUrl(sid, redirectUrl);
       res.redirect(ssoLogoutUrl);
     }
   });
@@ -178,7 +203,7 @@ const logoutHandler = async (req, res) => {
 
     // 로그아웃 URL을 생성 및 반환
     const redirectUrl = new URL(redirectPath, req.origin).href;
-    const ssoLogoutUrl = client.getLogoutUrl(sid, redirectUrl);
+    const ssoLogoutUrl = ssoClient.getLogoutUrl(sid, redirectUrl);
     logout(req, res);
     res.json({ ssoLogoutUrl });
   } catch (e) {
diff --git a/src/services/auth.mobile.js b/src/services/auth.mobile.js
index 6ae14db2..e2cee5bb 100644
--- a/src/services/auth.mobile.js
+++ b/src/services/auth.mobile.js
@@ -25,7 +25,7 @@ const tokenLoginHandler = async (req, res) => {
       return res.status(401).json({ message: "Not Access token" });
     }
 
-    const user = await userModel.findOne({ _id: data.id });
+    const user = await userModel.findOne({ _id: data.id, withdraw: false });
     if (!user) {
       return res.status(401).json({ message: "No corresponding user" });
     }
diff --git a/src/services/chats.js b/src/services/chats.js
index b6bd6467..d9631c9b 100644
--- a/src/services/chats.js
+++ b/src/services/chats.js
@@ -1,6 +1,5 @@
 const { chatModel, userModel, roomModel } = require("@/modules/stores/mongo");
 const { chatPopulateOption } = require("@/modules/populates/chats");
-const { roomPopulateOption } = require("@/modules/populates/rooms");
 const aws = require("@/modules/stores/aws");
 const {
   transformChatsForRoom,
@@ -14,17 +13,17 @@ const chatCount = 60;
 const loadRecentChatHandler = async (req, res) => {
   try {
     const io = req.app.get("io");
-    const { userId } = req;
+    const { userOid } = req;
     const { roomId } = req.body;
     const { id: sessionId } = req.session;
-    if (!userId) {
+    if (!userOid) {
       return res.status(500).send("Chat/ : internal server error");
     }
     if (!io) {
       return res.status(403).send("Chat/ : socket did not connected");
     }
 
-    const isPart = await isUserInRoom(userId, roomId);
+    const isPart = await isUserInRoom(userOid, roomId);
     if (!isPart) {
       return res
         .status(403)
@@ -56,10 +55,10 @@ const loadRecentChatHandler = async (req, res) => {
 const loadBeforeChatHandler = async (req, res) => {
   try {
     const io = req.app.get("io");
-    const { userId } = req;
+    const { userOid } = req;
     const { roomId, lastMsgDate } = req.body;
     const { id: sessionId } = req.session;
-    if (!userId) {
+    if (!userOid) {
       return res.status(500).send("Chat/load/before : internal server error");
     }
     if (!io) {
@@ -68,7 +67,7 @@ const loadBeforeChatHandler = async (req, res) => {
         .send("Chat/load/before : socket did not connected");
     }
 
-    const isPart = await isUserInRoom(userId, roomId);
+    const isPart = await isUserInRoom(userOid, roomId);
     if (!isPart) {
       return res
         .status(403)
@@ -100,17 +99,17 @@ const loadBeforeChatHandler = async (req, res) => {
 const loadAfterChatHandler = async (req, res) => {
   try {
     const io = req.app.get("io");
-    const { userId } = req;
+    const { userOid } = req;
     const { roomId, lastMsgDate } = req.body;
     const { id: sessionId } = req.session;
-    if (!userId) {
+    if (!userOid) {
       return res.status(500).send("Chat/load/after : internal server error");
     }
     if (!io) {
       return res.status(403).send("Chat/load/after : socket did not connected");
     }
 
-    const isPart = await isUserInRoom(userId, roomId);
+    const isPart = await isUserInRoom(userOid, roomId);
     if (!isPart) {
       return res
         .status(403)
@@ -141,18 +140,18 @@ const loadAfterChatHandler = async (req, res) => {
 const sendChatHandler = async (req, res) => {
   try {
     const io = req.app.get("io");
-    const { userId } = req;
+    const { userOid } = req;
     const { roomId, type, content } = req.body;
-    const user = await userModel.findOne({ id: userId });
+    const user = await userModel.findOne({ _id: userOid, withdraw: false });
 
-    if (!userId || !user) {
+    if (!userOid || !user) {
       return res.status(500).send("Chat/send : internal server error");
     }
     if (!io) {
       return res.status(403).send("Chat/send : socket did not connected");
     }
 
-    const isPart = await isUserInRoom(userId, roomId);
+    const isPart = await isUserInRoom(userOid, roomId);
     if (!isPart) {
       return res
         .status(403)
@@ -178,11 +177,11 @@ const sendChatHandler = async (req, res) => {
 const readChatHandler = async (req, res) => {
   try {
     const io = req.app.get("io");
-    const { userId } = req;
+    const { userOid } = req;
     const { roomId } = req.body;
-    const user = await userModel.findOne({ id: userId });
+    const user = await userModel.findOne({ _id: userOid, withdraw: false });
 
-    if (!userId || !user) {
+    if (!userOid || !user) {
       return res.status(500).send("Chat/read : internal server error");
     }
     if (!io) {
@@ -223,7 +222,7 @@ const readChatHandler = async (req, res) => {
 const uploadChatImgGetPUrlHandler = async (req, res) => {
   try {
     const { type, roomId } = req.body;
-    const user = await userModel.findOne({ id: req.userId });
+    const user = await userModel.findOne({ _id: req.userOid, withdraw: false });
     if (!roomId) {
       return res
         .status(403)
@@ -266,7 +265,7 @@ const uploadChatImgGetPUrlHandler = async (req, res) => {
 const uploadChatImgDoneHandler = async (req, res) => {
   try {
     const user = await userModel.findOne(
-      { id: req.userId },
+      { _id: req.userOid, withdraw: false },
       "_id nickname profileImageUrl"
     );
     const chat = await chatModel.findById(req.body.id).lean();
@@ -313,18 +312,17 @@ const uploadChatImgDoneHandler = async (req, res) => {
 /**
  * 주어진 유저가 주어진 방에 참여하는 중인지 확인합니다.
  * @summary 채팅 load/send 관련 api에서 검증을 위하여 함수로 분리하였습니다.
- * @param {string} userId - 확인하고픈 user의 Id 입니다.
+ * @param {string} userOid - 확인하고픈 user의 objectId 입니다.
  * @param {string} roomId - 참여하는지 확인하고픈 방의 objectId 입니다.
  * @return {Promise<Boolean>} userId가 방에 포함되어 있다면 true, 그 외의 경우 false를 반환합니다.
  */
-const isUserInRoom = async (userId, roomId) => {
-  const user = await userModel.findOne({ id: userId });
+const isUserInRoom = async (userOid, roomId) => {
   const { part } = await roomModel.findById(roomId);
 
-  if (!part || !user) return false;
+  if (!part) return false;
   return part
     .map((participant) => participant.user)
-    .some((user) => user.equals(user._id));
+    .some((user) => user.equals(userOid));
 };
 
 module.exports = {
diff --git a/src/services/logininfo.js b/src/services/logininfo.js
index affac40a..749f2e15 100644
--- a/src/services/logininfo.js
+++ b/src/services/logininfo.js
@@ -5,10 +5,10 @@ const logger = require("@/modules/logger").default;
 const logininfoHandler = async (req, res) => {
   try {
     const user = getLoginInfo(req);
-    if (!user.id) return res.json({ id: undefined });
+    if (!user.oid) return res.json({ id: undefined });
 
     const userDetail = await userModel.findOne(
-      { id: user.id },
+      { _id: user.oid, withdraw: false },
       "_id name nickname id withdraw phoneNumber ban joinat agreeOnTermsOfService subinfo email profileImageUrl account"
     );
 
diff --git a/src/services/notifications.js b/src/services/notifications.js
index fc2090cf..f0c4bf94 100644
--- a/src/services/notifications.js
+++ b/src/services/notifications.js
@@ -19,7 +19,10 @@ const registerDeviceTokenHandler = async (req, res) => {
     }
 
     // 데이터베이스에 deviceToken 레코드를 추가합니다.
-    const user = await userModel.findOne({ id: req.userId }, "_id");
+    const user = await userModel.findOne(
+      { _id: req.userOid, withdraw: false },
+      "_id"
+    );
     const newDeviceToken = await registerDeviceToken(user._id, deviceToken);
 
     // 세션에 현재 사용자 기기의 deviceToken을 저장합니다.
diff --git a/src/services/reports.js b/src/services/reports.js
index f4cb17f4..d0d707c2 100644
--- a/src/services/reports.js
+++ b/src/services/reports.js
@@ -8,10 +8,13 @@ const { notifyReportToReportChannel } = require("@/modules/slackNotification");
 const createHandler = async (req, res) => {
   try {
     const { reportedId, type, etcDetail, time, roomId } = req.body;
-    const user = await userModel.findOne({ id: req.userId });
+    const user = await userModel.findOne({ _id: req.userOid, withdraw: false });
     const creatorId = user._id;
 
-    const reported = await userModel.findById(reportedId);
+    const reported = await userModel.findOne({
+      _id: reportedId,
+      withdraw: false,
+    });
     if (!reported) {
       return res.status(400).json({
         error: "User/report: no corresponding user",
@@ -64,7 +67,7 @@ const createHandler = async (req, res) => {
 const searchByUserHandler = async (req, res) => {
   try {
     // 해당 user가 신고한 사람인지, 신고 받은 사람인지 기준으로 신고를 분리해서 응답을 전송합니다.
-    const user = await userModel.findOne({ id: req.userId });
+    const user = await userModel.findOne({ _id: req.userOid, withdraw: false });
     const response = {
       reporting: await reportModel
         .find({ creatorId: user._id })
diff --git a/src/services/rooms.js b/src/services/rooms.js
index 76350db0..7cc1370b 100644
--- a/src/services/rooms.js
+++ b/src/services/rooms.js
@@ -62,7 +62,7 @@ const createHandler = async (req, res) => {
 
     // 방 생성 요청을 한 사용자의 ObjectID를 room의 part 리스트에 추가
     const user = await userModel
-      .findOne({ id: req.userId })
+      .findOne({ _id: req.userOid, withdraw: false })
       .populate("ongoingRoom");
 
     // 사용자의 참여중인 진행중인 방이 5개 이상이면 오류를 반환합니다.
@@ -102,7 +102,7 @@ const createHandler = async (req, res) => {
     await emitChatEvent(req.app.get("io"), {
       roomId: room._id,
       type: "in",
-      content: user.id,
+      content: user._id,
       authorId: user._id,
     });
 
@@ -169,7 +169,9 @@ const createTestHandler = async (req, res) => {
     //   candidateRooms
     // );
     // if (isAbusing) {
-    //   const user = await userModel.findById(req.userOid).lean();
+    //   const user = await userModel
+    //     .findOne({ _id: req.userOid, withdraw: false })
+    //     .lean();
     //   notifyRoomCreationAbuseToReportChannel(
     //     req.userOid,
     //     user?.nickname ?? req.userOid,
@@ -211,13 +213,13 @@ const publicInfoHandler = async (req, res) => {
 
 const infoHandler = async (req, res) => {
   try {
-    const user = await userModel.findOne({ id: req.userId });
+    const user = await userModel.findOne({ _id: req.userOid, withdraw: false });
     const roomObject = await roomModel
       .findOne({ _id: req.query.id, "part.user": user._id })
       .lean()
       .populate(roomPopulateOption);
     if (roomObject) {
-      const isOver = getIsOver(roomObject, user.id);
+      const isOver = getIsOver(roomObject, user._id.toString());
       res.send(formatSettlement(roomObject, { isOver }));
     } else {
       res.status(404).json({
@@ -235,7 +237,7 @@ const infoHandler = async (req, res) => {
 const joinHandler = async (req, res) => {
   try {
     const user = await userModel
-      .findOne({ id: req.userId })
+      .findOne({ _id: req.userOid, withdraw: false })
       .populate("ongoingRoom");
 
     // 사용자의 참여중인 진행중인 방이 5개 이상이면 오류를 반환합니다.
@@ -297,7 +299,7 @@ const joinHandler = async (req, res) => {
     await emitChatEvent(req.app.get("io"), {
       roomId: room._id,
       type: "in",
-      content: user.id,
+      content: user._id,
       authorId: user._id,
     });
 
@@ -318,7 +320,7 @@ const abortHandler = async (req, res) => {
   };
 
   try {
-    const user = await userModel.findOne({ id: req.userId });
+    const user = await userModel.findOne({ _id: req.userOid, withdraw: false });
     const room = await roomModel.findById(req.body.roomId);
     if (!user) {
       res.status(400).json({
@@ -384,12 +386,12 @@ const abortHandler = async (req, res) => {
     await emitChatEvent(req.app.get("io"), {
       roomId: room._id,
       type: "out",
-      content: user.id,
+      content: user._id,
       authorId: user._id,
     });
 
     const roomObject = (await room.populate(roomPopulateOption)).toObject();
-    const isOver = getIsOver(roomObject, user.id);
+    const isOver = getIsOver(roomObject, user._id.toString());
 
     res.send(formatSettlement(roomObject, { isOver }));
   } catch (err) {
@@ -487,7 +489,7 @@ const searchByUserHandler = async (req, res) => {
   try {
     // lean()이 적용된 user를 response에 반환해줘야 하기 때문에 user를 한 번 더 지정한다.
     const user = await userModel
-      .findOne({ id: req.userId })
+      .findOne({ _id: req.userOid, withdraw: false })
       .populate({
         path: "ongoingRoom",
         options: {
@@ -527,7 +529,7 @@ const searchByUserHandler = async (req, res) => {
 
 const commitSettlementHandler = async (req, res) => {
   try {
-    const user = await userModel.findOne({ id: req.userId });
+    const user = await userModel.findOne({ _id: req.userOid, withdraw: false });
     const { roomId } = req.body;
     const roomObject = await roomModel
       .findOneAndUpdate(
@@ -583,7 +585,7 @@ const commitSettlementHandler = async (req, res) => {
     await emitChatEvent(req.app.get("io"), {
       roomId,
       type: "settlement",
-      content: user.id,
+      content: user._id,
       authorId: user._id,
     });
 
@@ -607,7 +609,7 @@ const commitSettlementHandler = async (req, res) => {
 const commitPaymentHandler = async (req, res) => {
   try {
     const { roomId } = req.body;
-    const user = await userModel.findOne({ id: req.userId });
+    const user = await userModel.findOne({ _id: req.userOid, withdraw: false });
     let roomObject = await roomModel
       .findOneAndUpdate(
         {
@@ -656,7 +658,7 @@ const commitPaymentHandler = async (req, res) => {
     await emitChatEvent(req.app.get("io"), {
       roomId,
       type: "payment",
-      content: user.id,
+      content: user._id,
       authorId: user._id,
     });
 
@@ -773,7 +775,7 @@ const checkIsSendRequired = (userObject) => {
 
 //   // Room update query에 사용할 filter입니다.
 //   // 방에 참여중인 인원만 방 정보를 수정할 수 있습니다.
-//   const user = await userModel.findOne({ id: req.userId }, "_id");
+//   const user = await userModel.findOne({ _id: req.userOid, withdraw: false }, "_id");
 //   const roomFilter = {
 //     _id: roomId,
 //     part: {
@@ -816,7 +818,7 @@ const checkIsSendRequired = (userObject) => {
 //     });
 //     if (result) {
 //       const roomObject = (await result.populate(roomPopulateOption)).toObject();
-//       const isOver = getIsOver(room, user.id);
+//       const isOver = getIsOver(room, user._id);
 //       res.send(formatSettlement(roomObject, { isOver }));
 //     } else {
 //       res.status(404).json({
diff --git a/src/services/users.ts b/src/services/users.ts
index 3caf35cf..bfc37e30 100644
--- a/src/services/users.ts
+++ b/src/services/users.ts
@@ -1,11 +1,13 @@
 import type { RequestHandler } from "express";
-import { userModel, banModel } from "@/modules/stores/mongo";
+import { ssoClient, getLoginInfo, logout } from "@/modules/auths/login";
+import { unregisterAllDeviceTokens } from "@/modules/fcm";
 import logger from "@/modules/logger";
 import {
   generateNickname,
   generateProfileImageUrl,
 } from "@/modules/modifyProfile";
 import * as aws from "@/modules/stores/aws";
+import { userModel, banModel } from "@/modules/stores/mongo";
 
 // 이벤트 코드입니다.
 // const { contracts } = require("@/lottery");
@@ -15,18 +17,24 @@ export const agreeOnTermsOfServiceHandler: RequestHandler = async (
   res
 ) => {
   try {
-    let user = await userModel.findOne({ id: req.userId });
+    let user = await userModel.findOne({ _id: req.userOid, withdraw: false });
     if (!user) {
       return res.status(400).send("Users/agreeOnTermsOfService : no such user");
     }
 
     if (user.agreeOnTermsOfService === true) {
-      return res.status(400).send("Users/agreeOnTermsOfService : already agreed");
+      return res
+        .status(400)
+        .send("Users/agreeOnTermsOfService : already agreed");
     }
 
     user.agreeOnTermsOfService = true;
     await user.save();
-    return res.status(200).send("Users/agreeOnTermsOfService : agree on Terms of Service successful");
+    return res
+      .status(200)
+      .send(
+        "Users/agreeOnTermsOfService : agree on Terms of Service successful"
+      );
   } catch {
     return res
       .status(500)
@@ -40,7 +48,7 @@ export const getAgreeOnTermsOfServiceHandler: RequestHandler = async (
 ) => {
   try {
     const user = await userModel
-      .findOne({ id: req.userId }, "agreeOnTermsOfService")
+      .findOne({ _id: req.userOid, withdraw: false }, "agreeOnTermsOfService")
       .lean();
     if (!user) {
       return res.status(400).send("Users/agreeOnTermsOfService : no such user");
@@ -59,7 +67,7 @@ export const editNicknameHandler: RequestHandler = async (req, res) => {
   try {
     const newNickname = req.body.nickname; // TODO: Typing
     const result = await userModel.findOneAndUpdate(
-      { id: req.userId },
+      { _id: req.userOid, withdraw: false },
       { nickname: newNickname }
     );
 
@@ -88,7 +96,7 @@ export const editAccountHandler: RequestHandler = async (req, res) => {
   try {
     const newAccount = req.body.account; // TODO: Typing
     const result = await userModel.findOneAndUpdate(
-      { id: req.userId },
+      { _id: req.userOid, withdraw: false },
       { account: newAccount }
     );
 
@@ -120,7 +128,10 @@ export const editProfileImgGetPUrlHandler: RequestHandler = async (
 ) => {
   try {
     const type = req.body.type; // TODO: Typing
-    const user = await userModel.findOne({ id: req.userId }, "_id");
+    const user = await userModel.findOne(
+      { _id: req.userOid, withdraw: false },
+      "_id"
+    );
     if (!user) {
       return res
         .status(500)
@@ -149,7 +160,10 @@ export const editProfileImgGetPUrlHandler: RequestHandler = async (
 
 export const editProfileImgDoneHandler: RequestHandler = async (req, res) => {
   try {
-    const user = await userModel.findOne({ id: req.userId }, "_id");
+    const user = await userModel.findOne(
+      { _id: req.userOid, withdraw: false },
+      "_id"
+    );
     if (!user) {
       return res
         .status(500)
@@ -164,7 +178,7 @@ export const editProfileImgDoneHandler: RequestHandler = async (req, res) => {
           .send("Users/editProfileImg/done : internal server error");
       }
       const userAfter = await userModel.findOneAndUpdate(
-        { id: req.userId },
+        { _id: req.userOid, withdraw: false },
         { profileImageUrl: aws.getS3Url(`/${key}?token=${req.timestamp}`) },
         { new: true }
       );
@@ -188,7 +202,7 @@ export const editProfileImgDoneHandler: RequestHandler = async (req, res) => {
 export const resetNicknameHandler: RequestHandler = async (req, res) => {
   try {
     const result = await userModel.findOneAndUpdate(
-      { id: req.userId },
+      { _id: req.userOid, withdraw: false },
       { nickname: generateNickname(req.body.id) }, // TODO: Typing or Validation
       { new: true }
     );
@@ -208,7 +222,7 @@ export const resetNicknameHandler: RequestHandler = async (req, res) => {
 export const resetProfileImgHandler: RequestHandler = async (req, res) => {
   try {
     const result = await userModel.findOneAndUpdate(
-      { id: req.userId },
+      { _id: req.userOid, withdraw: false },
       { profileImageUrl: generateProfileImageUrl() },
       { new: true }
     );
@@ -241,3 +255,38 @@ export const getBanRecordHandler: RequestHandler = async (req, res) => {
     return res.status(500).send("Users/getBanRecord : internal server error");
   }
 };
+
+export const withdrawHandler: RequestHandler = async (req, res) => {
+  try {
+    const { sid } = getLoginInfo(req);
+
+    const user = await userModel.findOne({ _id: req.userOid, withdraw: false });
+    if (!user) {
+      return res.status(500).send("Users/withdraw : internal server error");
+    }
+
+    // 회원 탈퇴가 가능한 조건인지 확인
+    if (user.withdraw) {
+      return res.status(400).send("Users/withdraw : already withdrawn");
+    } else if (user.ongoingRoom?.length !== 0) {
+      return res.status(400).send("Users/withdraw : ongoing room exists");
+    }
+
+    // 등록된 모든 디바이스 토큰 삭제
+    await unregisterAllDeviceTokens(req.userOid!);
+
+    // 회원 탈퇴 처리 (Soft Delete)
+    user.withdraw = true;
+    user.withdrewAt = new Date(req.timestamp!);
+    await user.save();
+
+    // 로그아웃 처리
+    const redirectUrl = new URL("/mypage?withdraw=true", req.origin).href;
+    const ssoLogoutUrl =
+      ssoClient?.getLogoutUrl(sid, redirectUrl) ?? redirectUrl;
+    logout(req);
+    res.json({ ssoLogoutUrl });
+  } catch (err) {
+    res.status(500).send("Users/withdraw : internal server error");
+  }
+};
diff --git a/src/types/index.d.ts b/src/types/index.d.ts
index d679d420..f8a54993 100644
--- a/src/types/index.d.ts
+++ b/src/types/index.d.ts
@@ -4,8 +4,6 @@ export {};
 declare global {
   namespace Express {
     export interface Request {
-      /** 사용자 ID. SPARCS SSO로부터 전달받습니다. */
-      userId?: string;
       /** 사용자의 ObjectID. MongoDB에서 사용됩니다. */
       userOid?: string;
       /** 요청의 origin. */
diff --git a/src/types/mongo.d.ts b/src/types/mongo.d.ts
index 718b342e..9848f4e0 100644
--- a/src/types/mongo.d.ts
+++ b/src/types/mongo.d.ts
@@ -1,6 +1,6 @@
 import type { Document, Types } from "mongoose";
 
-export interface User extends Document {
+export interface User extends Document<Types.ObjectId> {
   /** 사용자의 실명. */
   name: string;
   /** 사용자의 닉네임. */
@@ -15,6 +15,8 @@ export interface User extends Document {
   doneRoom?: Types.Array<Types.ObjectId>;
   /** 계정 탈퇴 여부. */
   withdraw: boolean;
+  /** 계정 탈퇴 시각. */
+  withdrewAt?: Date;
   /** 사용자의 전화번호. 2023 가을 이벤트부터 추가됨. */
   phoneNumber?: string;
   /** 계정 정지 여부. */
@@ -38,7 +40,7 @@ export interface User extends Document {
   account: string;
 }
 
-export interface Ban extends Document {
+export interface Ban extends Document<Types.ObjectId> {
   /** 정지된 사용자의 ID. */
   userSid: string;
   /** 정지 사유. */
@@ -57,7 +59,7 @@ export type SettlementStatus =
   | "send-required"
   | "sent";
 
-export interface Participant extends Document {
+export interface Participant extends Document<Types.ObjectId> {
   /** 방 참여자의 User ObjectID. */
   user: Types.ObjectId;
   /** 방 참여자의 정산 상태. */
@@ -66,14 +68,14 @@ export interface Participant extends Document {
   readAt?: Date;
 }
 
-export interface DeviceToken extends Document {
+export interface DeviceToken extends Document<Types.ObjectId> {
   /** 디바이스 토큰 소유자의 User ObjectID. */
   userId: Types.ObjectId;
   /** 소유한 디바이스 토큰의 배열. */
   deviceTokens: Types.Array<string>;
 }
 
-export interface NotificationOption extends Document {
+export interface NotificationOption extends Document<Types.ObjectId> {
   deviceToken: string;
   /** 채팅 알림 수신 여부. */
   chatting: boolean;
@@ -87,13 +89,13 @@ export interface NotificationOption extends Document {
   advertisement: boolean;
 }
 
-export interface TopicSubscription extends Document {
+export interface TopicSubscription extends Document<Types.ObjectId> {
   deviceToken?: string;
   topic?: string;
   subscribedAt: Date;
 }
 
-export interface Room extends Document {
+export interface Room extends Document<Types.ObjectId> {
   /** 방의 이름. */
   name: string;
   /** 방의 출발지의 Location ObjectID. */
@@ -112,7 +114,7 @@ export interface Room extends Document {
   maxPartLength: number;
 }
 
-export interface Location extends Document {
+export interface Location extends Document<Types.ObjectId> {
   enName: string;
   koName: string;
   priority: number;
@@ -134,7 +136,7 @@ export type ChatType =
   | "departure"
   | "arrival";
 
-export interface Chat extends Document {
+export interface Chat extends Document<Types.ObjectId> {
   /** 메세지가 전송된 방의 Room ObjectID. */
   roomId: Types.ObjectId;
   /** 메세지의 종류. */
@@ -146,7 +148,7 @@ export interface Chat extends Document {
   isValid: boolean;
 }
 
-export interface Report extends Document {
+export interface Report extends Document<Types.ObjectId> {
   /** 신고한 사용자의 ObjectID. */
   creatorId: Types.ObjectId;
   /** 신고받은 사용자의 ObjectID. */
@@ -161,14 +163,14 @@ export interface Report extends Document {
   roomId?: Types.ObjectId;
 }
 
-export interface AdminIPWhitelist extends Document {
+export interface AdminIPWhitelist extends Document<Types.ObjectId> {
   ip: string;
   description: string;
 }
 
 export type AdminLogAction = "create" | "read" | "update" | "delete";
 
-export interface AdminLog extends Document {
+export interface AdminLog extends Document<Types.ObjectId> {
   /** 로그 발생자의 User ObjectID. */
   user: Types.ObjectId;
   /** 로그의 발생 시각. */
@@ -181,7 +183,7 @@ export interface AdminLog extends Document {
   action: AdminLogAction;
 }
 
-export interface TaxiFare extends Document {
+export interface TaxiFare extends Document<Types.ObjectId> {
   /** 출발지의 Location ObjectID. */
   from: Types.ObjectId;
   /** 목적지의 Location ObjectID. */
diff --git a/test/services/reports.js b/test/services/reports.js
index 86347d4a..96c9aa42 100644
--- a/test/services/reports.js
+++ b/test/services/reports.js
@@ -18,7 +18,7 @@ describe("[reports] 1.createHandler", () => {
     const testRoom = await roomGenerator("test1", testData);
     const msg = "User/report : report successful";
     let req = httpMocks.createRequest({
-      userId: testUser1.id,
+      userOid: testUser1._id,
       body: {
         reportedId: testUser2._id,
         type: "etc-reason",
@@ -41,7 +41,7 @@ describe("[reports] 2.searchByUserHandler", () => {
   it("should return correct reporting/reported reports of users", async () => {
     const testUser1 = await userModel.findOne({ id: "test1" });
     let req = httpMocks.createRequest({
-      userId: testUser1.id,
+      userOid: testUser1._id,
     });
     let res = httpMocks.createResponse();
     await reportHandlers.searchByUserHandler(req, res);
diff --git a/test/services/rooms.js b/test/services/rooms.js
index 4e948ad1..894901da 100644
--- a/test/services/rooms.js
+++ b/test/services/rooms.js
@@ -31,7 +31,7 @@ describe("[rooms] 1.createHandler", () => {
         time: Date.now() + 60 * 1000,
         maxPartLength: 4,
       },
-      userId: testUser1.id,
+      userOid: testUser1._id,
       app,
     });
     let res = httpMocks.createResponse();
@@ -51,7 +51,7 @@ describe("[rooms] 2.infoHandler", () => {
     const testRoom = await roomModel.findOne({ name: "test-room" });
     let req = httpMocks.createRequest({
       query: { id: testRoom._id },
-      userId: testUser1.id,
+      userOid: testUser1._id,
     });
     let res = httpMocks.createResponse();
     await roomsHandlers.infoHandler(req, res);
@@ -87,7 +87,7 @@ describe("[rooms] 4.joinHandler", () => {
       body: {
         roomId: testRoom._id,
       },
-      userId: testUser2.id,
+      userOid: testUser2._id,
       app,
     });
     let res = httpMocks.createResponse();
@@ -129,7 +129,7 @@ describe("[rooms] 6.searchByUserHandler", () => {
   it("should return information of searching room", async () => {
     const testUser1 = await userModel.findOne({ id: "test1" });
     let req = httpMocks.createRequest({
-      userId: testUser1.id,
+      userOid: testUser1._id,
     });
     let res = httpMocks.createResponse();
     await roomsHandlers.searchByUserHandler(req, res);
@@ -147,7 +147,7 @@ describe("[rooms] 7.commitSettlementHandler", () => {
     const testRoom = await roomModel.findOne({ name: "test-room" });
     let req = httpMocks.createRequest({
       body: { roomId: testRoom._id },
-      userId: testUser1.id,
+      userOid: testUser1._id,
       timestamp: Date.now() + 60 * 1000,
       app,
     });
@@ -168,7 +168,7 @@ describe("[rooms] 8.commitPaymentHandler", () => {
     const testRoom = await roomModel.findOne({ name: "test-room" });
     let req = httpMocks.createRequest({
       body: { roomId: testRoom._id },
-      userId: testUser2.id,
+      userOid: testUser2._id,
       app,
     });
     let res = httpMocks.createResponse();
@@ -188,7 +188,7 @@ describe("[rooms] 9.abortHandler", () => {
     const testRoom = await roomModel.findOne({ name: "test-room" });
     let req = httpMocks.createRequest({
       body: { roomId: testRoom._id },
-      userId: testUser2.id,
+      userOid: testUser2._id,
       session: {},
       app,
     });
diff --git a/test/services/users.js b/test/services/users.js
index 4f2195da..2cf3245e 100644
--- a/test/services/users.js
+++ b/test/services/users.js
@@ -17,7 +17,7 @@ describe("[users] 1.agreeOnTermsOfServiceHandler", () => {
     const msg =
       "Users/agreeOnTermsOfService : agree on Terms of Service successful";
     let req = httpMocks.createRequest({
-      userId: testUser1.id,
+      userOid: testUser1._id,
     });
     let res = httpMocks.createResponse();
     await usersHandlers.agreeOnTermsOfServiceHandler(req, res);
@@ -33,7 +33,7 @@ describe("[users] 2.getAgreeOnTermsOfServiceHandler", () => {
   it("should return AgreeOnTermsOfService of user", async () => {
     const testUser1 = await userModel.findOne({ id: "test1" });
     let req = httpMocks.createRequest({
-      userId: testUser1.id,
+      userOid: testUser1._id,
     });
     let res = httpMocks.createResponse();
     await usersHandlers.getAgreeOnTermsOfServiceHandler(req, res);
@@ -52,7 +52,7 @@ describe("[users] 3.editNicknameHandler", () => {
     const testUser1 = await userModel.findOne({ id: "test1" });
     const msg = "Users/editNickname : edit user nickname successful";
     let req = httpMocks.createRequest({
-      userId: testUser1.id,
+      userOid: testUser1._id,
       body: {
         nickname: testNickname,
       },
@@ -79,7 +79,7 @@ describe("[users] 4.editAccountHandler", () => {
     const testUser1 = await userModel.findOne({ id: "test1" });
     const msg = "Users/editAccount : edit user account successful";
     let req = httpMocks.createRequest({
-      userId: testUser1.id,
+      userOid: testUser1._id,
       body: {
         account: testAccount,
       },
@@ -105,7 +105,7 @@ describe("[users] 5.editProfileImgGetPUrlHandler", () => {
     const testUser1 = await userModel.findOne({ id: "test1" });
     const testImgType = "image/jpg";
     let req = httpMocks.createRequest({
-      userId: testUser1.id,
+      userOid: testUser1._id,
       body: {
         type: testImgType,
       },
@@ -129,7 +129,7 @@ describe("[users] 6.editProfileImgDoneHandler", () => {
   it("should return correct result and new profileImageUrl", async () => {
     const testUser1 = await userModel.findOne({ id: "test1" });
     let req = httpMocks.createRequest({
-      userId: testUser1.id,
+      userOid: testUser1._id,
     });
     let res = httpMocks.createResponse();
     await usersHandlers.editProfileImgDoneHandler(req, res);
diff --git a/tsconfig.build.json b/tsconfig.build.json
index 68db80dd..0e742aa9 100644
--- a/tsconfig.build.json
+++ b/tsconfig.build.json
@@ -1,4 +1,8 @@
 {
   "extends": "./tsconfig.json",
-  "include": ["src"],
+  "compilerOptions": {
+    "incremental": true,
+    "tsBuildInfoFile": ".tsbuildinfo"
+  },
+  "include": ["src"]
 }
diff --git a/tsconfig.json b/tsconfig.json
index 166f2de6..63239482 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -18,6 +18,7 @@
   "include": ["src", "scripts"],
   "exclude": ["dist", "node_modules"],
   "ts-node": {
-    "files": true
+    "files": true,
+    "transpileOnly": true
   }
 }