An image forming apparatus having a compact size includes a printing medium supplying unit to hold printing media and to supply a printing medium, an image forming unit disposed above the printing medium supplying unit to form images on a printing medium, and a printing medium feeding part substantially formed in a letter “C” shape, having a part which extends to the image forming unit and which is inclined in a downward direction along a printing medium moving direction to feed the printing medium from the printing medium supplying unit to the image forming unit.