A cooking device is provided which blows most of the air blown from a circulation fan in a heater room to a heater, such that the heating of air by the heater is facilitated and the volume of the rear side of a heater case is reduced to permit manufacture of the cooking device in a small size. The cooking device includes a heater case provided to form a heater room in an inner case, a circulation fan installed in the heater room, a heater installed outside of the circulation fan in the heater room, a motor mounted outside the heater case and driving the circulation fan, and a first sunken part formed such that a portion of the heater case, on which the motor is mounted, is sunken inward with respect to the heater room by a predetermined depth.