An image forming apparatus includes: a printing unit for making printing on a print medium; a communicating unit for communicating with an external apparatus; a controlling unit for controlling the image forming apparatus; a storing unit for storing print data which is used by the printing unit; and a power controlling unit for transferring the image forming apparatus to a power saving state in which power supply to the controlling unit and the storing unit is stopped. The communicating unit outputs a first signal to the power controlling unit in a case where a destination port number of data received from the external apparatus in the power saving state is a predetermined port number, and the power controlling unit supplies power at least to the storing unit in response to input of the first signal.