PURPOSE: To simplify the lighting control for the remote control unit which gives the lighting control to the illuminators or the like, by installing the mike on the upper surface of the load opposing to the ceiling surface.

CONSTITUTION: Microphone 18 is installed to illuminator 13 attached to ceiling 11 at the upper surface of the illuminator, that is, the position opposing to the ceiling surface. Thus the ultrasonic signals sent from remote control transmitter 19 are reflected on wall surface 12 and ceiling surface 11 to be received at mike 18. Thus the accurate control becomes unnecessary for the illuminating direction of the ultrasonic signals sent from the transmitter. As a result, the lighting operation can be simplified greatly.