Patent attributes
A vacuum valve comprises: a housing configured such that a flow path of gas passing through a pair of opposing openings is formed; a valve body; a sealing body; a sealing body drive section configured to drive the sealing body in upstream and downstream directions of the gas; and a mechanical stopper including a restriction section configured to inhibit, at a restriction position, movement of the sealing body in the gas downstream direction. The mechanical stopper is disposed movable to a selected one of a first position at which movement of the sealing body toward a gas downstream side is inhibited at the restriction position or a second position at which movement of the sealing body from the restriction position to a non-restriction position on the gas downstream side is allowed.