diff --git a/cloudbuild.yaml b/cloudbuild.yaml
index 28caf78..3b0e4ce 100644
--- a/cloudbuild.yaml
+++ b/cloudbuild.yaml
@@ -25,7 +25,7 @@ steps:
         "--image",
         "${_REGION}-docker.pkg.dev/${PROJECT_ID}/${_REPOSITORY}/${_SERVICE_NAME}:${TAG_NAME}",
         "--set-env-vars",
-        "ENVIRONMENT=${_ENVIRONMENT},ALLOW_ORIGIN=${_ALLOW_ORIGIN},TRUSTED_PROXY=${_TRUSTED_PROXY},FIREBASE_PROJECT_ID=${PROJECT_ID}",
+        "ENVIRONMENT=${_ENVIRONMENT},ALLOW_ORIGIN=${_ALLOW_ORIGIN},TRUSTED_PROXY=${_TRUSTED_PROXY},GOOGLE_CLOUD_PROJECT_ID=${PROJECT_ID}",
         "--region",
         "${_REGION}",
         "--service-account",
diff --git a/cmd/app/main.go b/cmd/app/main.go
index 1bcf8fc..4c4862e 100644
--- a/cmd/app/main.go
+++ b/cmd/app/main.go
@@ -26,7 +26,7 @@ func main() {
 	gotenv.Load(fmt.Sprintf(".env.%v", mode))
 	gotenv.Load(fmt.Sprintf(".env.%v.local", mode))
 
-	err := db.InitDatabaseClient(os.Getenv("FIREBASE_PROJECT_ID"))
+	err := db.InitDatabaseClient(os.Getenv("GOOGLE_CLOUD_PROJECT_ID"))
 	if err != nil {
 		log.Fatalf("Failed to initialize database: %v", err)
 	}
@@ -48,5 +48,13 @@ func main() {
 
 	router.POST("/api/hello-world", api.HelloWorldHandler)
 
-	router.Run(":8080")
+	err = router.Run(":8080")
+	if err != nil {
+		log.Fatalf("Failed to run gin server: %v", err)
+	}
+
+	err = db.FinalizeDatabaseClient()
+	if err != nil {
+		log.Fatalf("Failed to finalize database: %v", err)
+	}
 }
diff --git a/internal/api/hello_world_test.go b/internal/api/hello_world_test.go
index 73f70de..02ef22a 100644
--- a/internal/api/hello_world_test.go
+++ b/internal/api/hello_world_test.go
@@ -8,6 +8,7 @@ import (
 	"strings"
 	"testing"
 
+	"cloud.google.com/go/firestore"
 	"github.com/gin-gonic/gin"
 	"github.com/kumachan-mis/knodeledge-api/internal/db"
 	"github.com/kumachan-mis/knodeledge-api/internal/model"
@@ -15,8 +16,9 @@ import (
 )
 
 func TestMain(m *testing.M) {
-	db.InitDatabaseClient("test-project-id")
+	db.InitDatabaseClient(firestore.DetectProjectID)
 	m.Run()
+	db.FinalizeDatabaseClient()
 }
 
 func TestHelloWorldHandler(t *testing.T) {
diff --git a/internal/db/client.go b/internal/db/client.go
index 014c6aa..3dac88c 100644
--- a/internal/db/client.go
+++ b/internal/db/client.go
@@ -4,21 +4,38 @@ import (
 	"context"
 
 	"cloud.google.com/go/firestore"
+	firebase "firebase.google.com/go"
 )
 
 var firestoreClient *firestore.Client
 var firestoreContext context.Context
 
-func InitDatabaseClient(projectId string) error {
-	firestoreContext = context.Background()
-	client, err := firestore.NewClient(firestoreContext, projectId)
+func InitDatabaseClient(projectID string) error {
+	ctx := context.Background()
+	conf := &firebase.Config{ProjectID: projectID}
+
+	app, err := firebase.NewApp(ctx, conf)
+	if err != nil {
+		return err
+	}
+
+	client, err := app.Firestore(ctx)
 	if err != nil {
 		return err
 	}
+
 	firestoreClient = client
+	firestoreContext = ctx
 	return nil
 }
 
+func FinalizeDatabaseClient() error {
+	err := firestoreClient.Close()
+	firestoreClient = nil
+	firestoreContext = nil
+	return err
+}
+
 func FirestoreClient() *firestore.Client {
 	return firestoreClient
 }