An electric rice cooker is disclosed which includes a cooking kettle for containing rice and water, a removable lid member covering the top of the kettle, a heater provided adjacent to the outer bottom surface of the kettle to heat the kettle, and a thermistor for measuring the actual kettle temperature. A cooking amount measuring circuit for detecting the actual amount of kettle contents every time a cooking operation is performed, and a control circuit for controlling the operation of the heater by determining the proper time at which the heater should be turned OFF in accordance with actually measured data obtained during the cooking operation which is being performed, are arranged in a case.