PURPOSE: To reduce the burden on an inspector for maintenance.

CONSTITUTION: A supply voltage monitor means 15 which monitors the supply voltage applied to a power supply line by a receiver and changes the output in accordance with this supply voltage and an emitted light intensity control means 16 which changes the intensity of emitted light of an infrared light emitting diode LED1 as the light emitting element in accordance with the output of the supply voltage monitor means 15 are provided, and the alarm raising operation is artificially performed by the prescribed change of the supply voltage. Thus, the maintenance work is facilitated because the operation of a photoelectric smoke sensor is inspected by the remote control from the receiver.