An image forming apparatus includes an image forming portion for forming an unfixed toner image on a recording material; and a fixing portion for heat-fixing the unfixed toner image on the recording material while nip-conveying the recording material in a fixing nip, the fixing portion includes a first rotatable member contactable to the unfixed toner image, and a second rotatable member contacted to the first rotatable member to form the fixing nip between itself and the first rotatable member. The image forming apparatus is capable of setting a cleaning mode in which the fixing portion is cleaned by a cleaning sheet while nip-conveying the cleaning sheet in the fixing nip. When the cleaning mode is set, the image forming apparatus executes a plurality of types of cleaning operations in a period in which a single cleaning sheet passes through the fixing nip.