A spacer, which is an atmospheric pressure resistant structure for a vacuum container, can be easily assembled, and the manufacturing costs that accompany the installation of the spacer are reduced. Either one of the two bearings includes an outer ring and an inner ring both of which are electrically insulated from each other. In addition, the polyimide high-temperature bonding layer laminate may be adhered to a poly adhesive primer layer to more effectively bond the polyimide core layer to the high-temperature bonding layer.