How to call other Activity in main activity

==> Activity call function
public void call()
{
        Intent intent = new Intent(this, Start_Activity.class);
        startActivity(intent);
}

==> Intent file modify in the AndroidManifest.xml

<intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
</intent-filter>