PURPOSE: To perform the drying of a food, in a short time, by energizing a heater for the heating of the food intermittently, and heating the food with microwave during the intermission period of the heater.

CONSTITUTION: The start key of the operation key board 51 is pushed down to start the heating of the food with the heater 20 by energizing the magnetic coils 47c, 48c and 49c via the control circuit, and at the same time, to start the circulation and ventilation of the drying chamber by energizing the motors 19a and 21a and driving the stirrer fan 19b and the ventilation fan 21b. On the other hand, the timer is started to start the count-down of the time, and when the temperature in the chamber detected by the temperature sensor 25 is raised to the upper limit, the coil 49c is demagnetized to cut the heater 20, and the magnetic coil 45c is energized to energize the magnetron 18 and heat the food by microwave. When the temperature in the chamber is lowered to the lower limit, the heater 20 is switched on and the magnetron 18 is switched off. The drying of the food placed on a shelf 26 can be carried out by the procedure at a high temperature maintained within a preset range.