An image forming apparatus includes a plurality of image bearing members, replaceable development units, replaceable toner replenishing members, toner supply units, and a control unit. The development units are each provided for a corresponding one of the plurality of image bearing members. The toner replenishing members are each provided for a corresponding one of the development units. The toner supply units are arranged between the respective toner replenishing members and the development units. The control unit causes the image forming apparatus to execute a toner supply unit cleaning mode to convey a last-used toner inside the toner supply unit into the development unit which is last used and to be replaced to empty the toner supply unit, when replacement of the development unit and the corresponding toner replenishing member is designated to use a toner of a type different from the last-used toner.