An image forming apparatus includes a sheet conveying device configured to convey a sheet along a conveying path, a fixing roller configured to perform thermal fixing on the sheet having unfixed toner, a motor configured to rotationally drive the fixing roller, a first sheet detector disposed downstream from the fixing roller, a second sheet detector provided between the first sheet detector and the fixing roller and where the second sheet detector does not detect the sheet when the sheet is being properly conveyed, and a controller configured to perform motor stopping methods for stopping the driving of the motor, wherein the methods providing different motor stopping capabilities. When the first sheet detector is not detecting the sheet at a predetermined timing, the controller selects from the methods on the basis of a detection result of the second sheet detector.