diff --git a/app/src/main/java/com/example/cosmosclient/app/Cosmos.java b/app/src/main/java/com/example/cosmosclient/app/Cosmos.java
index ede712b..d5c271d 100644
--- a/app/src/main/java/com/example/cosmosclient/app/Cosmos.java
+++ b/app/src/main/java/com/example/cosmosclient/app/Cosmos.java
@@ -5,6 +5,7 @@
 import com.example.cosmosclient.entities.AreaInformation;
 import com.example.cosmosclient.entities.Group;
 import com.example.cosmosclient.entities.Location;
+import android.content.SharedPreferences;
 
 import java.util.HashMap;
 
@@ -19,10 +20,15 @@
 
     //token処理
     public void setToken(String token){
-        this.token = token;
+        SharedPreferences prefData = getSharedPreferences("pref_data", MODE_PRIVATE);
+        SharedPreferences.Editor editor = prefData.edit();
+        editor.putString("token", token);
+        editor.commit();
     }
 
     public String getToken(){
+        SharedPreferences prefData = getSharedPreferences("pref_data", MODE_PRIVATE);
+        String token = prefData.getString("token", "");
         return token;
     }
 
@@ -50,10 +56,15 @@
 
     //uId処理
     public void setuId(String uId){
-        this.uId = uId;
+        SharedPreferences prefData = getSharedPreferences("pref_data", MODE_PRIVATE);
+        SharedPreferences.Editor editor = prefData.edit();
+        editor.putString("uId", uId);
+        editor.commit();
     }
 
     public String getuId(){
+        SharedPreferences prefData = getSharedPreferences("pref_data", MODE_PRIVATE);
+        String uId = prefData.getString("uId", "");
         return uId;
     }
 
diff --git a/app/src/main/java/com/example/cosmosclient/views/GroupListActivity.java b/app/src/main/java/com/example/cosmosclient/views/GroupListActivity.java
index 0ff3b5b..aa105e2 100644
--- a/app/src/main/java/com/example/cosmosclient/views/GroupListActivity.java
+++ b/app/src/main/java/com/example/cosmosclient/views/GroupListActivity.java
@@ -1,7 +1,6 @@
 package com.example.cosmosclient.views;
 
 import android.content.Intent;
-import android.content.SharedPreferences;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.nfc.Tag;
@@ -347,10 +346,8 @@
             startActivity(intent);
         } else if (id == R.id.signOutButton){
             //トークン削除
-            SharedPreferences prefData = getSharedPreferences("pref_data", MODE_PRIVATE);
-            SharedPreferences.Editor editor = prefData.edit();
-            editor.remove("token");
-            editor.commit();
+            Cosmos app = (Cosmos) getApplication();
+            app.setToken("");
             gridView.stopEditMode();
             Intent intent=new Intent(GroupListActivity.this, com.example.cosmosclient.views.SigninActivity.class);
             ActivityCompat.finishAffinity(GroupListActivity.this);
diff --git a/app/src/main/java/com/example/cosmosclient/views/SigninActivity.java b/app/src/main/java/com/example/cosmosclient/views/SigninActivity.java
index 400555d..5a1198d 100644
--- a/app/src/main/java/com/example/cosmosclient/views/SigninActivity.java
+++ b/app/src/main/java/com/example/cosmosclient/views/SigninActivity.java
@@ -7,7 +7,6 @@
 import android.Manifest;
 import android.content.Context;
 import android.content.Intent;
-import android.content.SharedPreferences;
 import android.content.pm.PackageManager;
 import android.os.Build;
 import android.os.Handler;
@@ -72,9 +71,8 @@
         final EditText PasswordText = findViewById(R.id.PasswordText);
         Button ForgotPasswordButton = findViewById(R.id.ForgotPasswordButton);
 
-        // 「pref_data」という設定データファイルを読み込み
-        SharedPreferences prefData = getSharedPreferences("pref_data", MODE_PRIVATE);
-        String account = prefData.getString("account", "");
+        Cosmos app = (Cosmos) getApplication();
+        String account  = app.getuId();
 
         // 空チェック
         if (account != null && account.length() > 0) {
@@ -133,13 +131,6 @@
                                 app.setToken(result.token);
                                 app.setuId(UserIdText.getText().toString());
 
-                                //SharedPreferencesに情報保存
-                                SharedPreferences prefData = getSharedPreferences("pref_data", MODE_PRIVATE);
-                                SharedPreferences.Editor editor = prefData.edit();
-                                editor.putString("account", UserIdText.getText().toString());
-                                editor.putString("token", result.token);
-                                editor.commit();
-
                                 //画面遷移
                                 Intent intent = new Intent(getApplication(), GroupListActivity.class);
                                 startActivity(intent);
diff --git a/app/src/main/java/com/example/cosmosclient/views/SignupActivity.java b/app/src/main/java/com/example/cosmosclient/views/SignupActivity.java
index afa76b9..bafa874 100644
--- a/app/src/main/java/com/example/cosmosclient/views/SignupActivity.java
+++ b/app/src/main/java/com/example/cosmosclient/views/SignupActivity.java
@@ -2,7 +2,6 @@
 
 
 import android.content.Intent;
-import android.content.SharedPreferences;
 import android.graphics.Bitmap;
 import android.net.Uri;
 import android.os.Handler;
@@ -112,18 +111,6 @@
                             Cosmos app = (Cosmos) getApplication();
                             app.setToken(result.token);
                             app.setuId(result.uId);
-                            //データをprerefarenceに保存
-
-                            // 「pref_data」という設定データファイルを読み込み
-                            SharedPreferences prefData = getSharedPreferences("pref_data", MODE_PRIVATE);
-                            SharedPreferences.Editor editor = prefData.edit();
-
-                            // 入力されたログインIDとログインパスワード
-                            editor.putString("account", result.uId);
-                            editor.putString("token", result.token);
-
-                            // 保存
-                            editor.commit();
 
                             Intent intent = new Intent(getApplication(), GroupListActivity.class);
                             startActivity(intent);