Image forming apparatus and return control method for returning each part from energy saving state by determining usage status of function by user

A return control method executed by an image forming apparatus capable of switching between an energy saving mode and a normal mode that consumes more power than the energy saving mode,

• the image forming apparatus having
• an operation panel that allows a user to operate and instruct,
• a document reading unit that reads a mounted document according to the user's scanning instruction, and
• an image forming unit that forms an image on the recording paper according to the output instruction of the user, and
• the method comprising the steps of:
• determining whether or not power is supplied depending on usage status of function by the user, and,
• controlling, when returning from the energy saving mode to the normal mode, each of the power supplies of the operation panel unit, the document reading unit, and the image forming unit to be turned on or off according to determination, wherein
• the usage status of function is determined based on presence or absence of a job for which an image is to be formed, function used immediately before, initial screen setting, and function mainly used.