The present invention provides a seat belt retractor, seat belt apparatus, and seat belt winding method, which has improved reliability of the seat belt winding-up performance and still can reduce the frequency of unnecessary actuations of a motor; the seat belt retractor of the present invention comprises a control unit (123) which stops actuation of the motor when an overload of the motor is detected during the winding-up of a seat belt and restarts the actuation of the motor after a lapse of a predetermined time period. The control unit (123) comprises a getting-on/off action detecting section (401) which detects an action of an occupant for getting on or off a vehicle and a retry determining section (405) which determines, using criteria, whether or not it is required to restart the actuation of the motor which is stopped by detection of the overload; the criteria for the case that the occupant gets on the vehicle and for the case that the occupant gets off the vehicle are different from each other. The criteria are provided such that the retry determining section (405) likely determines that it is not required to restart the actuation of the motor in the case that the occupant gets on the vehicle as compared to the case that the occupant gets off the vehicle.