diff --git a/app/src/main/java/com/example/cosmosclient/views/SigninActivity.java b/app/src/main/java/com/example/cosmosclient/views/SigninActivity.java
deleted file mode 100644
index 2fed0e0..0000000
--- a/app/src/main/java/com/example/cosmosclient/views/SigninActivity.java
+++ /dev/null
@@ -1,46 +0,0 @@
-package com.example.cosmosclient.views;
-
-import android.content.Intent;
-import android.support.v7.app.AppCompatActivity;
-import android.os.Bundle;
-import android.view.View;
-import android.widget.Button;
-import android.widget.EditText;
-
-import com.example.cosmosclient.R;
-
-public class SigninActivity extends AppCompatActivity {
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_signin);
-
-        //各種IDを取得
-        Button SigninButton = findViewById(R.id.SigninButton);
-        Button SignupButton = findViewById(R.id.SignupButton);
-        EditText EmailAddressText = findViewById(R.id.EMailAddressText);
-        EditText PasswordText = findViewById(R.id.PasswordText);
-        Button ForgotPasswordButton = findViewById(R.id.ForgotPasswordButton);
-
-        //Sign inボタンの処理
-        SigninButton.setOnClickListener(new View.OnClickListener() {
-            @Override
-            public void onClick(View v) {
-                Intent intent = new Intent(getApplication(), GroupList.class);
-                startActivity(intent);
-                finish();
-            }
-        });
-
-        //サインアップ画面への遷移処理
-        SignupButton.setOnClickListener(new View.OnClickListener(){
-            @Override
-            public void onClick(View v){
-                Intent intent = new Intent(getApplication(), SignupActivity.class);
-                startActivity(intent);
-                finish();
-            }
-        });
-    }
-}