To provide an energy saving type smaller vacuum device, and to develop the technology of a circuit device for delivering the performance of a vacuum pump.

A container referred to as a sucker is connected to the small vacuum pump, and the sucker is previously brought to the highest vacuum by the vacuum pump. A vacuum suction pipe circuit to a braising cooker is suddenly opened so that the sucker instantly sucks steam. Thus, sudden pressure drop gives boiling promotion effects to water in processed materials to urge cooling and drying.