PURPOSE: To facilitate the handleability of a cooking utensil as well as raise the energy conservation of the utensil by controlling heat source by detecting a vibration resulting from sounds emitting when ebullition bubbles are broken by means of a vibration sensor in a detection circuit.

CONSTITUTION: A pan 1 is provided with a metal vibration transmitter 5 of good vibration transmissibility, a vibration sensor 6 consisting of a speed pick up meter, etc., sensitive to vibration, connected to the vibration sensor 6, a detection circuit 7 to detect vibration produced at the time of ebullition, and a control circuit 8 to control the power source circuit 9 of a heat source 3 according to a signal from the detection circuit. The detection circuit 7 puts a vibration signal received in a vibration sensor 6 into an input terminal 11, and then a capacitor 15 is electrically charged after cutting unnecessary portion by a wave detection circuit 12, etc. When a peak value of voltage is held in the capacitor 15, it is connected through an amplifier circuit 16 to a control circuit 17 and the control circuit 8 controls the heat source through the power source circuit 9.