To adjust a gas of a certain flow rate excellent in the reproducibility of a full close state due to no plastic deformation.
This valve opening and closing device in which a gas flow passage 3 is formed is provided with a valve element 2 having a piston 6 at the flow passage and a valve seat 4 for contacting with and separating from the valve element and a gas flow rate is controlled by making the valve element and the valve seat contact with and separate from each other. The valve opening and closing device is provided with a driving body 9 by which the valve element presses the valve seat by pressure equal to or lower than predetermined pressure in the case that the movement of a piston is controlled and the valve element is in contact with the valve seat. The vacuum processing device is provided with the valve opening and closing device.
KOMATA HIROSHI
Hiroshi Shimura
Michio Nagai