A power saving mode includes a plurality of levels that are different in recovery time to a normal mode and in power consumption of a main body system. The plurality of levels are set to correspond to remaining heat temperature of a fixing device so that the recovery time to the normal mode becomes shorter as the remaining heat temperature is higher, and the power consumption of the main body system becomes lower as the remaining heat temperature is lower. Depending on a change in the remaining heat temperature, a power control section switches to a level corresponding to the remaining heat temperature, of the plurality of levels of the power saving mode of the main body system.