An image forming apparatus operating in a double-sided print mode, includes a charger for charging an image carrier, a charge voltage loader for applying a charge voltage to the charger, an image forming device for forming an image on a recording material, and a controller for controlling the charge voltage applied by the charge voltage loader to the charger. When an image is formed on both sides of a plurality of recording materials, the controller changes the charge voltage applied by the charge voltage loader from a first to a second voltage when an image is formed on first and second sides of the recording material in a period in which an image is formed on the recording sheet, and does not change the charge voltage during an interval between a first recording material and a second recording material to the second charge voltage.