Certain embodiments provide an image forming apparatus including: a print process part; a heat roller including a heating element; a press roller including a heater; a power source part having a power upper limit value that is smaller than a sum of heating power for the heat roller and the press roller plus initial power and is larger than the heating power; a power source control part to control supply or stop of the initial power; a plurality of temperature sensors to detect respective roller temperatures; and a determination part to determine necessity of supplying the initial power by the power source control part based on a temperature difference between the respective roller temperatures.