An image forming apparatus includes an openable cover capable of opening and closing an opening, an image forming portion for forming a toner image on a sheet, and a cam member provided in the image forming portion for moving a contact member toward and away from an opposing member. A controller controls the image forming portion and rotation of the cam member. The controller stops an operation of the image forming portion when a detecting unit detects opening of the openable cover, and then controls rotation of the cam member at least one full turn when the detecting unit detects closing of the openable cover.