An image forming apparatus includes: a plurality of photosensitive members; at least one retaining member configured to temporarily retain remaining developer remaining on a corresponding photosensitive member; a belt arranged opposite to the plurality of photosensitive members; a cleaning device configured to collect developer on the belt; a remaining developer collecting unit configured to cause the remaining developer retained by the retaining member to be transferred onto the belt via the photosensitive member and thereafter to be collected by the cleaning device; and a plurality of developing devices each including a development chamber in which is provided a developing roller for supplying developer to the corresponding photosensitive member, and a developer storage chamber arranged above the development chamber and configured to store developer. Each development device includes a circulation mechanism configured to circulate developer between the development chamber and the developer storage chamber.