A cooking device body having a heating chamber for heating an object; a fan for discharging air in the heating chamber; and an exhaust duct for guiding air blown off from said fan to the outside of the cooking device body are provided, an opening is provided at a wall of said exhaust duct, and the fan is constructed to have a motor disposed outside the exhaust duct, a first plate which has a central side attached to the motor and an outer edge side attached to the periphery of the opening, a bladed wheel which is attached to the output shaft of the motor and disposed in the exhaust duct, and a second plate which defines a cavity between said bladed wheel and the first plate.