An image forming apparatus capable of minimizing a temperature rise of a cover by substantially preventing heat emission from a fusing device to an outside is disclosed. The image forming apparatus includes a main body, a fusing device mounted in the main body, the fusing device having an outlet to discharge paper, an opening/closing member opening and closing the outlet of the fusing device, a cam member moving the opening/closing member between a first position in which the opening/closing member closes the outlet to prevent heat in the fusing device from being emitted through the outlet and a second position in which the opening/closing member opens the outlet to permit the paper to pass through the outlet, a driving part rotating the cam member, and a control unit controlling the driving part to determine a rotational position of the cam member.