To cause an image formation apparatus which has an external controller and supports a power saving state to recover from the power saving state without losing any piece of data even when it is in the power saving state when a printing request or the like from an external device is received via the external controller.

When the external controller 10 receives print data from a client PC 15, the external controller 10 changes a power saving recovery signal 19 from a High level (nonactive) to a Low level (active). When a power saving control function unit 20 in a controller unit 5 of the image formation apparatus 1 detects it, power control signals 18 and 23 are changed from the High level to the Low level so as to send them to a FET 17 and a FET 16 which feed power to the controller unit 5 and an engine unit 4, respectively. At this point, the FET 17 and the FET 16 are turned ON, and the image formation apparatus 1 recovers from the power saving state.