diff --git a/app/src/main/java/com/example/oplogy/FirestoreReception.java b/app/src/main/java/com/example/oplogy/FirestoreReception.java
index 1082f09..232bfb7 100644
--- a/app/src/main/java/com/example/oplogy/FirestoreReception.java
+++ b/app/src/main/java/com/example/oplogy/FirestoreReception.java
@@ -27,6 +27,7 @@ public class FirestoreReception {
 
     //ClassIdを引数にデータの作成を行う
     public void getDocumentsByClassId(int classId) {
+        myDataList.clear();
         CollectionReference collectionRef = db.collection("QuestionnaireForms");
 
         // classIdが引数のものを取得する
diff --git a/app/src/main/java/com/example/oplogy/MainActivity.java b/app/src/main/java/com/example/oplogy/MainActivity.java
index b844925..e759dc1 100644
--- a/app/src/main/java/com/example/oplogy/MainActivity.java
+++ b/app/src/main/java/com/example/oplogy/MainActivity.java
@@ -84,10 +84,6 @@ public class MainActivity extends AppCompatActivity implements View.OnClickListe
         db = FirebaseFirestore.getInstance();
         firestoreReception = new FirestoreReception();
 
-        if(classId!=100000){
-            firestoreReception.getDocumentsByClassId(classId);
-        }
-
     }
 
 
@@ -107,6 +103,7 @@ public class MainActivity extends AppCompatActivity implements View.OnClickListe
         if(view == setUp){
             imageSetup.setImageResource(R.drawable.ischecked_uuid);
             Intent toSetup = new Intent(MainActivity.this,SetUpActivity.class);
+            toSetup.putExtra("classId", classId);
             startActivity(toSetup);
             finish();   // 画面遷移後元の状態に戻す
         }
@@ -177,7 +174,7 @@ public class MainActivity extends AppCompatActivity implements View.OnClickListe
 
         CountDownLatch latch = new CountDownLatch(2);
 
-        // タスク1: ローカルDBから生徒数を取得
+        // タスク1: ローカルDBから生徒数を取得してtotalStudentと比較
         executor.execute(() -> {
             AppDatabase db = Room.databaseBuilder(getApplicationContext(), AppDatabase.class, "SetUpTable").build();
             SetUpTableDao setUpTableDao = db.setUpTableDao();
@@ -196,7 +193,7 @@ public class MainActivity extends AppCompatActivity implements View.OnClickListe
             });
         });
 
-        // タスク2: Firestoreからデータを取得
+        // タスク2: ルート作成を行う
         executor.execute(() -> {
             List<MyDataClass> myDataList = null;
             while (myDataList == null) {
@@ -341,9 +338,15 @@ public class MainActivity extends AppCompatActivity implements View.OnClickListe
     @Override
     protected void onResume(){
         super.onResume();
-        if (classId != 100000) {
+        //roomからclassIdを取得
+        ExecutorService executor = Executors.newSingleThreadExecutor();
+        executor.execute(() -> {
+            AppDatabase db = Room.databaseBuilder(getApplicationContext(), AppDatabase.class, "SetUpTable").build();
+            SetUpTableDao setUpTableDao = db.setUpTableDao();
+            classId = setUpTableDao.getClassId();
+        });
+        if (classId != 100000 ) {
             firestoreReception.getDocumentsByClassId(classId);
         }
     }
-
 }
\ No newline at end of file
diff --git a/app/src/main/java/com/example/oplogy/SetUpActivity.java b/app/src/main/java/com/example/oplogy/SetUpActivity.java
index 8b3385d..851d0f1 100644
--- a/app/src/main/java/com/example/oplogy/SetUpActivity.java
+++ b/app/src/main/java/com/example/oplogy/SetUpActivity.java
@@ -50,6 +50,8 @@ public class SetUpActivity extends FragmentActivity
 
 
 
+
+
     Button startTimeSetButton;
     Button endTimeSetButton;
 
@@ -61,6 +63,8 @@ public class SetUpActivity extends FragmentActivity
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_set_up);
 
+        int classId= getIntent().getIntExtra("classId", 100000);
+
         setTeacherName = findViewById(R.id.teacherName);                    //先生の名前
         setStartPoint = findViewById(R.id.startPoint);                      //開始地点
 
@@ -139,7 +143,8 @@ public class SetUpActivity extends FragmentActivity
                         intervalTime,
                         startBreakTime,
                         endBreakTime,
-                        totalStudent
+                        totalStudent,
+                        classId
                 );
 
                 // 同じ名前のエントリが存在するかどうかを確認
diff --git a/app/src/main/java/com/example/oplogy/SetUpTable.java b/app/src/main/java/com/example/oplogy/SetUpTable.java
index a61ed27..dfb21ad 100644
--- a/app/src/main/java/com/example/oplogy/SetUpTable.java
+++ b/app/src/main/java/com/example/oplogy/SetUpTable.java
@@ -16,12 +16,12 @@ public class SetUpTable {
     public String endBreakTime;
     public int totalStudent;
 
-    //TODO: ここのコードをあとで実装する。roomにString classIdの作成
+    int classId;
 
 
     //コンストラクタ
     public SetUpTable(String teacherName, String startPoint, String startTime, String endTime,
-                        String intervalTime, String startBreakTime, String endBreakTime, int totalStudent) {
+                        String intervalTime, String startBreakTime, String endBreakTime, int totalStudent,int classId) {
         this.teacherName = teacherName;
         this.startPoint = startPoint;
         this.startTime = startTime;
@@ -30,6 +30,7 @@ public class SetUpTable {
         this.startBreakTime = startBreakTime;
         this.endBreakTime = endBreakTime;
         this.totalStudent = totalStudent;
+        this.classId = classId;
     }
     //getter
     public int getId() {
diff --git a/app/src/main/java/com/example/oplogy/SetUpTableDao.java b/app/src/main/java/com/example/oplogy/SetUpTableDao.java
index ec59624..5c21478 100644
--- a/app/src/main/java/com/example/oplogy/SetUpTableDao.java
+++ b/app/src/main/java/com/example/oplogy/SetUpTableDao.java
@@ -39,4 +39,7 @@ public interface SetUpTableDao {
     String getStartBreakTime();
     @Query("SELECT EndBreakTime FROM SetUpTable")
     String getEndBreakTime();
+    //クラスIDの取得
+    @Query("SELECT classId FROM SetUpTable")
+    int getClassId();
 }