In this invention, an apparatus of which the power supply is in the off state is remotely controlled through a communications network. Each of one or a plurality of controlled apparatus has a ROM for holding the MAC address of the controlled apparatus, and a network control IC that reads out the MAC address from the ROM and transmits it through a LAN to a control apparatus. The control apparatus receives the one or plurality of MAC addresses from the one or plurality of controlled apparatus through the LAN, stores the received one or plurality of MAC addresses in a cache memory and controls the one or plurality of controlled apparatus by using the one or plurality of MAC addresses stored in the cache memory.