A transfer device having a structure for preventing the meandering of a transfer belt, an image forming apparatus including a structure for preventing the meandering of a transfer belt, and a method for preventing meandering of the transfer belt. The image forming apparatus including a main body. The main body including an image forming member and a transfer device which transfers an image formed through the image forming member to a printing medium. The transfer device includes a frame, a driving roller, a backup roller being rotatably supported to the frame, a transfer belt to travel between the driving roller and the backup roller; and meandering prevention members located at both end portions of the backup roller to independently rotate. The meandering prevention members being driven by contact with the transfer belt to control tension of the transfer belt.