When electric power supply is started in response to a power switch being turned on, a control unit determines whether a stored operation mode is a normal mode or a power saving mode with reference to the stored operation mode. More specifically, the control unit determines whether a digital multifunction peripheral is set to operate in the normal mode or the power saving mode before electric power supply to the digital multifunction peripheral is stopped. If the set operation mode is the normal mode, the control unit controls the digital multifunction peripheral to operate in the normal mode. If the set operation mode is the power saving mode, the control unit controls the digital multifunction peripheral to operate in the power saving mode.