PURPOSE: To cook delicious rice gruel automatically either from rice or from boiled rice only by selecting a key switch.

CONSTITUTION: At the start of cooking of rice gruel, the timer is switched on and water absorption process starts; the water absorption process ends after elapse of a specified water absorption time during which the heating electric power of heater is lowered gradually against the rise of temperature in the inner pot. Then, in the cooking process, the standard cooking curve is previously established to determine the rise of temperature in the inner pot up to boiling and the heating electric power of heater is controlled so that the temperature in the inner pot rises in accordance with the standard cooking curve, by detecting the temperature in the inner pot and always comparing it with the temperature on the standard cooking curve through the cooking process; different conditions for cooking rice gruel are specified in connection with the control depending on whether it is cooked from rice or from boiled rice and rice gruel is cooked under the control of heating electric power of heater based upon the cooking condition so specified.