PURPOSE: To improve external appearance in a room by securing the holder of an electronic apparatus to a switch box buried in a wall surface in the room, and closing the opening of the box by the holder.

CONSTITUTION: A switch box 12 is buried in and secured to a wall 8 in a room. The sizes of a lead hole 13, the box 12, the size between screw holes 15 of a mounting piece 14, etc., are determined according to JIS. A holder 10 is brought into contact with the hole 16 of a wall 8, a screw 21 is engaged with the hole 15 of the piece 14, and engaged with a rubber cover 22. Then, the holder 10 is seen to be seemed to be mounted on the wall surface. The size of the holder 10 is determined by the JIS, and substantially coincides with the opening area of the box 12. When the engaging pawl 24 of the holder 10, a mount base 25 are used to engage the groove 26 of the side face of a remote controller 11 with the pawl 24, the controller 11 can be secured to the holder 10 to improve its external appearance.