HIGH VACUUM DRAWING METHOD AND VACUUM DEVICE

PURPOSE:To minimize the number of gas molecules, reduce the leak into a vessel, and highly evacuate the vessel by providing a double vessel, and drawing a vacuum also between the vessels. CONSTITUTION:A vacuum device is provided with a double vessel 1, a vacuum pump 3 for drawing a vacuum in the space 1a between the outer wall and inner wall of the double vessel 1, and a pump 2 for drawing a vacuum in the vessel 1. By using the vessel as the double vessel 1 in this method and drawing a vacuum also between the vessels, the number of gas molecules is minimized, and the leak into the vessel is reduced. In this example, two vacuum pumps are utilize, but only one pump may be used to alternately draw a vacuum between the vessels and the vessel inner part by the opening and closing operation of a valve. Thus, the vessel inner part can be highly evacuated.