An electronic device may include a housing including a first surface facing a first direction and a second surface facing a second direction, the first direction being opposite that of the second direction, the first surface including a first opening and a second opening; a touch screen display being disposed and visible through the first opening; a mechanical button located at least in part of the second opening and movable in response to a pressure applied thereto; a processor located inside the housing and electrically coupled to the display and the mechanical button; and a memory located inside the housing and electrically coupled to the processor, wherein the memory stores a plurality of instructions that cause, upon execution, the processor to: display a screen on at least a portion of the touch screen display; display a virtual button comprising a graphical user interface (GUI) on a specific region of the screen adjacent to the mechanical button such that the GUI visually extends the mechanical button.