In accordance with an embodiment, an image forming apparatus encompasses a heat roller, a lamp, a use amount acquisition section, a switching controller and a cycle controller. The heat roller heats a sheet printed with a toner image. The lamp heats the heat roller. The use amount acquisition section acquires a use amount of the lamp. The switching controller repeats a processing from a moment at which the lamp is charged until the lamp is charged next after the lamp is not charged in a predetermined control cycle. The cycle controller sets the cycle based on the use amount.