PURPOSE: To view the use states of plural OA equipments without coming to the respective OA equipments by filling transmitters which differ in transmission frequency and generate fine-level outputs to the OA equipments, respectively, and displaying the outputs of the transmitters on a display board or power distribution board on the same floor.

CONSTITUTION: This system consists of the transmitters T1-T6 which correspond to plural OA equipments OA1-OA6 and transmit fine radio waves of mutually different frequencies and the display board 1 equipped with a receiving antenna 3 provided in the ceiling on the floor, light emission bodies L1-Le6 which correspond to the OA equipments OA1-OA6, and a receiver 2. Then, the corresponding light emission bodies L1-L6 are made to illuminate and the use states of the OA equipments OA1-OA6 are viewed. If the OA3 is powered on and used, the light emission body L3 on the display board 1 illuminates. Consequently, which OA equipment is in use can be viewed by looking at the display board 1.