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 08b6688..0ff3b5b 100644
--- a/app/src/main/java/com/example/cosmosclient/views/GroupListActivity.java
+++ b/app/src/main/java/com/example/cosmosclient/views/GroupListActivity.java
@@ -1,6 +1,7 @@
 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;
@@ -345,6 +346,11 @@
             Intent intent=new Intent(GroupListActivity.this, com.example.cosmosclient.views.JoinGroupActionsActivity.class);
             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();
             gridView.stopEditMode();
             Intent intent=new Intent(GroupListActivity.this, com.example.cosmosclient.views.SigninActivity.class);
             ActivityCompat.finishAffinity(GroupListActivity.this);