PURPOSE: To reduce the cost and to facilitate the maintenance work, e.g., inspection of an electric device box and a service, by a method wherein an electric device box mounting device to mount the electric device box on the side of an air conditioner body is commonly used for both of a ceiling flush type and a wall flus type.

CONSTITUTION: An electric device box 11 disposed to the side of an air conditioner body 1 embedded in a ceiling 4 or a wall 9 is held by an electric device body holding member 12 so as to allow horizontal pull out thereof. Further, a guide member verti cally movably guides and holds the electric device holding member 12 and holding the holding member at a lower end and comprises first and second guide members 14 and 15. A securing tool removably secures the electric device box 11 and comprises a securing member 17 and a securing screw 19. The the guide member and the securing tool are mounted on the side of the air conditioner body 1. Thus, an electric device box mounting device to mount the electric device box 11 on the side of the air condi tioner body 1 can be commonly used for both of a ceiling flush type and a wall flush type. Further, the electric device box 11 can be pulled out both to a position below an opening surface 4a of a ceiling 4 and a position in front of the opening surface of a wall 9.