diff --git a/AgileWorks/AgileWorks/Login/View/LoginViewController.swift b/AgileWorks/AgileWorks/Login/View/LoginViewController.swift
index b475d2baae924625af013508963ab0deae5442d1..326bd0052a445c3e21c099bd5e482acf782fa138 100644
--- a/AgileWorks/AgileWorks/Login/View/LoginViewController.swift
+++ b/AgileWorks/AgileWorks/Login/View/LoginViewController.swift
@@ -166,7 +166,12 @@ class LoginViewController: UIViewController {
                 self.registDevice()
             case .failure(let error):
                 log.e(error)
-                self.showLoginError(isLogout: false)
+                let error = error as! OAuthError
+                if error != .loginCancel {
+                    self.showLoginError(isLogout: false)
+                } else {
+                    self.enableLogin()
+                }
             }
         }
     }
diff --git a/AgileWorks/Common/OAuthService.swift b/AgileWorks/Common/OAuthService.swift
index 6141dc13517e9211cb2cfaab114964e53293f079..078679976a433beb5f2236aeed921a077964376e 100644
--- a/AgileWorks/Common/OAuthService.swift
+++ b/AgileWorks/Common/OAuthService.swift
@@ -15,6 +15,7 @@ public enum OAuthError: Error {
     case oauthError
     case accessTokenError
     case sessionIdError
+    case loginCancel
 }
 
 public class OAuthService: NSObject {
@@ -41,7 +42,7 @@ public class OAuthService: NSObject {
                                               responseType: OIDResponseTypeCode,
                                               additionalParameters: nil)
 
-        OAuthService.currentAuthorizationFlow = OIDAuthState.authState(byPresenting: request, presenting: viewController!) { authState, _ in
+        OAuthService.currentAuthorizationFlow = OIDAuthState.authState(byPresenting: request, presenting: viewController!) { authState, error in
             if let authState = authState {
                 self.setAuthState(authState)
                 log.debug(authState)
@@ -59,7 +60,16 @@ public class OAuthService: NSObject {
                 completion(.success(()))
             } else {
                 self.setAuthState(nil)
-                completion(.failure(.oauthError))
+                if let error = error as? NSError {
+                    //ユーザーがOAuth認証コードフローを手動でキャンセル
+                    if error.code == OIDErrorCode.userCanceledAuthorizationFlow.rawValue {
+                        completion(.failure(.loginCancel))
+                    } else {
+                        completion(.failure(.oauthError))
+                    }
+                } else {
+                    completion(.failure(.oauthError))
+                }
             }
         }
     }