According to one embodiment, an image forming apparatus includes an image forming unit, a fixing unit, a reading unit, and a control unit. The image forming unit forms a visible image on a sheet. The fixing unit executes a fixing process of fixing the visible image on the sheet. The reading unit executes a reading process of reading an image. The control unit starts measurement of time until shift to a power saving mode, and shifts the operation mode to the power saving mode in which power consumption is suppressed when the measured time passes a predetermined set time. The control unit stops the measurement of the time during execution of printing, which is a process involving execution of the fixing process, and continues the measurement of the time during execution of the reading process without execution of the printing.