an image forming capable of operating with reliability and shortening the down time . an operation unit forms an image . a power source unit supplies electric power supplied from an external power source to the operation unit . a storing unit stores successful data which shows that the image forming apparatus has started successfully . a mode selection unit selects a first mode in which regular electric power is supplied to the operation unit at a start - up when the storing unit stores the successful data , and a second mode in which electric power smaller than the regular electric power is supplied to the operation unit at the start - up when the storing unit does not store the successful data . a power control unit controls the electric power supplied from the power source unit to the operation unit according to the mode selected by the mode selection unit .