An image forming apparatus includes: a main casing; a belt unit having a belt and a belt cleaning unit; a waste toner container; and a supporting member supporting the waste toner container and a cartridge storing toner supplied to a photosensitive member. The supporting member in the main casing is movable between a contact position where the photosensitive member contacts the belt and a separation position where the photosensitive member separates from the belt. One of the waste toner container and the belt cleaning unit is movable between a connected position providing connection to each other and a disconnected position providing disconnection from each other when the support member is in the contact position. The supporting member moves between the contact position and the separation position when one of the waste toner container and the belt cleaning unit is in the disconnected position.