PURPOSE: To control cooking in the finishing condition suiting user's preference at all times by installing a changing means which causes a set value stored by a memory to be changed on the basis of the finishing result of articles to be heated and causes its value to be stored as a new set value.

CONSTITUTION: A menu is selected by a menu selection key 2 on an operation part 1 and heating is started by pushing a start key 5. Then, the temp. or humidity of steam is detected by a detecting means 6 fort heating and its value is sent to a comparison part 7. At the means 7 this detected and a set value previously stored by a memory 8 are compared and when the detected value is equal to the set value, a stop signal is sent to a stop means 9 for heating to finish heating. A user evaluates the finishing condition of food and selects finishing evaluation from among four-step keys for the finishing evaluation 4aW4d. Thereby, the evaluation value of the finishing evaluation key is sent to a means 10 for changing memory and the content in the memory 8 is changed to meet the evaluation result. Next time, a new set value is compared with a detected value and the finishing suiting user's preference can be obtained.