An image forming apparatus includes an engine unit which is used to perform an image forming job; a controller which controls an operation of the engine unit; a step motor which operates the engine unit; a storage unit which stores an acceleration table including pulse per second (PPS) information of each of driving speeds of the step motor; and a driving controller which generates a driving signal of the step motor according to a control command of the step motor which is received from the controller. The driving controller generates the driving signal by using PPS information corresponding to a speed change section of the acceleration table corresponding to the control command.