If You dont want click on that Image, Then you can use drawableRight
property for EditText..
android:drawableRight="@drawable/icon"
If you want click then use below code.
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Enter search key" />
<ImageButton
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:src="https://stackoverflow.com/questions/13151366/@drawable/search"
android:layout_centerVertical="true"
android:layout_margin="5dp"
android:text="Button"/>
</RelativeLayout>