An image forming apparatus includes a controller that controls rotational driving of a magnetic roller and rotational driving of a developing roller. The controller is capable of performing a toner collecting mode when no image formation is performed. In the toner collecting mode, the magnetic roller and the developing roller are intermittently rotated in a direction reverse to a direction in which the magnetic roller and the developing roller are rotated during image formation, then the magnetic roller is made to rotate in a forward direction, and then, the magnetic roller is rotated in a backward direction.