A belt driving apparatus includes: a drive pulley that is attached to an output shaft of a drive motor and has teeth formed on the outer peripheral surface thereof; a driven pulley that is spaced apart from the drive pulley; an endless belt that is wound between the drive pulley and the driven pulley and is configured of a timing belt; a tension pulley that is provided on an upstream side in the vicinity of the drive pulley and comes in contact with the outer peripheral surface of the endless belt on an upstream side to apply tension to the endless belt; and a winding angle maintaining member that is provided on a downstream side in the vicinity of the drive pulley and on the side of the outer peripheral surface of the belt to maintain the winding angle of the endless belt with respect to the drive pulley.