An image forming apparatus having at least a normal mode and an energy saving mode of less energy consumption than the normal mode includes: a main controller executing image processing in the normal mode and stopping operation in the energy saving mode; energy saving controller controlling the image forming apparatus in the energy saving mode; nonvolatile storage unit connected to the main controller; volatile storage unit connected to the main controller and the energy saving controller; and network communication unit connected to the energy saving controller to perform network communication. The nonvolatile storage unit stores a MAC address with which the energy saving controller controls the network communication unit. The main controller writes the MAC address stored in the nonvolatile storage unit into the volatile storage unit during startup of the apparatus. The energy saving controller controls the network communication unit based on the transferred MAC address.