Electronic equipment, software updating method, program, and recording medium

An electronic apparatus has a normal mode and an energy saving mode for reducing power consumption, and includes a main control unit, a sub control unit, a main storage unit, and a sub storage unit. The sub control unit includes a processing unit performing a part of an update process by storing software update data in the sub storage unit when a software update request is received during the energy saving mode. The main control unit includes a processing unit performing a rest of the update process by moving or copying the software update data from the sub storage unit to the main storage unit and by updating software stored in the main storage unit with the software update data after the electronic apparatus returns from the energy saving mode to the normal mode.