An image forming apparatus, including an image forming section, a fixing unit, a memory section and a control section having a cleaning mode, wherein after the sheet is conveyed to the image forming section, the control section controls the image forming section not to form an image on the sheet, and the sheet is conveyed to the fixing unit, after which the control section controls to clean the fixing member by removing remaining toner, and when sheet jamming is caused at the fixing unit while the cleaning mode is practiced, the control section controls the memory section to store at least one characteristic of the sheet that causes the sheet jamming, and when a succeeding cleaning mode is practiced, the control section prohibits selection of the sheet having the characteristic stored in the memory section, and selects the sheet having other characteristics to practice the cleaning mode.