PURPOSE: To improve the time efficiency of automatic cookig utensil equipped with a moisture and gas sensor and the like, by constituting such that a sensor element may be cleaned after a cooking start signal is inputted and the ventilation of heating compartment may be stopped until the sensor recovers its sensing capability.

CONSTITUTION: An operation is started to clean a sensor simultaneously with a continuous heating of heat-cooking utensil after its cooking operation is started. The ventilation fan of heating compartment is kept inoperative until the sensor recovers its sensing capability. That is, the fan is rendered inoperative at the moment that a relative humidity inside the heating compartment is increased. This manner of operation can raise a humidity inside a room. Upon the sensor recovering its sensing capability, the fan is brought into operation again. All these controls are performed by microcomputer. This constitution can eliminate the risk of smoking and firing because the utensil emits no exhaust gas while the senser lacks its sensing capability, whereby permitting the utensil to heat a foodstuff continuously after started and to improve its time efficiency.