An image forming apparatus includes a mounting portion that detachably mounts either one of a fixing portion and another fixing portion. Each fixing portion includes a first rotatable member and a second rotatable member that, together, form a nip for fixing a toner image on a sheet, and a memory. A rubbing rotatable member executes a rubbing process of rubbing a surface of the first rotatable member, and a moving mechanism moves the rubbing rotatable member between a rubbing position, in which the rubbing rotatable member is in contact with the first rotatable member, and a stand-by position, in which the rubbing rotatable member is separated from the first rotatable member. In addition, a controller stores information corresponding to an execution frequency of the rubbing process designated by an operator through an operating panel, in the memory of the fixing portion that has been mounted in the mounting portion.