Patent ID: 7797807

Claim:
A method for manufacturing a double-layer vacuum which includes an outer container and an inner container forming a metal double-layer container, and a vacuum space provided between the inner container and the outer container, the method comprising: bonding a lip of the inner container to a lip of the outer container, such that the inner container is supported at a bonded portion bonded to the outer container; supporting the inner container by the outer container by extending a bridging member from the inner container to the outer container externally in a bridging manner; covering a portion of the outer container through which the bridging member is exposed with a cover member, and providing a sealing material between the cover member and the portion of the outer container so as to leave a vacuum-pumping path through the sealing material; evacuating a space inside the cover member and a space between the inner container and the outer container through the vacuum-pumping path in a vacuum-pump furnace; and sealing a boundary between the cover member and the outer container with the sealing material so as to close the vacuum-pumping path by flow of the sealing material.