PURPOSE: To keep an oil temperature close to a set temperature by arranging an oil temperature sensor for detecting the oil temperature, a heater temperature sensor for detecting the temperature of a heater, and a controller for forecasting the oil temperature after a specified time, from a difference between the oil temperature and heater temperature measured with the sensors, and controlling the generated heat quantity of the heater.

CONSTITUTION: In a frying pot, a heater temperature sensor 11 for measuring a heater temperature close to a heater 3 is set, and on the internal surface of a pot 2, an oil temperature sensor 12 for measuring an oil temperature is set. By a processor 13, temperature information fed from the temperature sensor are stored and are discriminated to be compared with a set temperature, and according to its result, a temperature controlling switch 10 is worked, the heater is turned ON or OFF. When the heater temperature TH gets higher than the oil temperature TO by 60°C or higher, then there is the possibility of the oil temperature TO which rises continuously due to the extra heat of the heater even if the heater 3 is turned OFF, and so a device is controlled so that a difference between the heater temperature TH and the oil temperature TO cannot exceed 60°C.