An image forming apparatus is provided, in which communication history that may change in a sleep mode is updated and displayed, whereby state of data communication in the sleep mode can be grasped. Even if the image forming apparatus as a whole is stopped, power is supplied only to a communication unit. When data is transmitted/received from an external device, a communication controller of the communication unit that transmitted/received data temporarily drives an electronic paper, so that transmission/reception log is displayed on electronic paper. Thereafter, power supply to the electronic paper is stopped.