To prevent vacuum troubles due to poor connection between an ion gauge to measure the degree of a vacuum in a source and an ion gauge port, breakage or poor connection to/between the ion gauge or/and the ion gauge port during changing work for the ion gauge, long-time changing work in processes during changing the ion gauge port and the increase in cost.
A mounting portion 18 of a gate valve 10 is connected to one end of the ion gauge port 24 of an ion gauge port 14 with a coupling 26 to be disconnectable. One other end of the SUS(stainless steel) ion gauge port 24 is connected to a glass ion gauge mounting hole 22 in an ion gauge 12 with screwing using a SUS nut 28 in such a manner that a male screw 34 cut at the other end of the SUS ion gauge port 24 is screwed in a female screw 36 at the SUS nut 28.
KIHARA NOBUO
OKAMOTO SHIRO
OSAKA HIROSHI
