PURPOSE: To set up a lighting sensor for illuminance adjusting control indication of a hallway light in a hallway lighting mechanism without damaging its function and in a modest way in order to improve designability arround the hallway.

CONSTITUTION: A lighting sensor 10 is set up by mounting it on a hallway door horn 12. Then, a detection signal about the presence of a man in the hallway region from this lighting sensor 10 is made to be delivered to a dimming circuit 16. Thereby, lowering of the appearance of a mounting part when the lighting sensor 10 is in dependently mounted and lowering of freedom of a design of a hallway light in case of settingup on the hallway light 14 can be prevented, as a result, the appearance a found the hallway can be improved.