PURPOSE: To surely avoid risks caused by the user's forgetting to switch off the fryer or forgetting that the fryer is still being used, and to automatically adjust the time for frying according to the volume of the food to be fried.

CONSTITUTION: When the heating is started, an oil tank 5 is at the lower position so that the food stored in a basket 4 will not touch the cooking oil in the oil tank 5. When a temperature detector 9 detects that the temperature of the cooking oil has reached a prescribed temperature and inputs the signal to a controller, the controller will operate a lifter 6 to lift the oil tank 5 up to the upper position and control a magnetron 7 so that the temperature of the cooking oil in the oil tank 5, which has been moved up to the upper position, will be kept at the prescribed level.