Abstract: A cooking appliance including both a resistive heating element and a high-frequency wave source such as a microwave generator in which a metal skewer is easily insertable through a front opening in a heating chamber and in which changes in dimensions in supporting members for the skewer are absorbed totally. A ceramic coupling member extends between a polygonally-shaped rotary shaft end and the metal skewer with a coupling hole in the coupling member being detachably insertable over the polygonally-shaped rotary shaft end. The skewer extends into a through-hole in the coupling member which has a shape similar to that of the skewer. A spring is provided to urge the coupling member outwardly into engagement with the rotary shaft end.