PURPOSE: To improve the fermenting finishing result of bread and the like, by constituting a composite cooking utensil and the like which consists of a gas oven and an electronic oven such that an external air introduced by a fan may pass the vicinity of compartment temperature detecting device.

CONSTITUTION: A fan motor 7 introduces an external air into a compartment through a punching section provided at the backside plate. The external air subsequently passes the vicinity of temperature detector 15 while cooling a magnetron 4. In this manner, the external air is utilized to cool the magnetron 4 when the utensil is used as an electronic oven. When the utensil is used merely as an oven, the external air cools the upper board of the body. At this moment, the temperature detector 15 shifts the temperature inside a heating compartment 2 either to a higher or lower level depending on the corelation between the external air and the temprature inside the heating compartment in order to compensate for the environmental influences. As a result, it is made possible to maintain the bread surface temperature after fermented at constant irrespectively of any external air temperature, whereby improving the bread finishing quality.