Vacuum processing apparatus

A vacuum processing apparatus comprising:

• a plurality of pairs of normally closed air-driven valves;
• and
• a gas supply unit that supplies gas, for performing vacuum processing using the plurality of normally closed type air-driven valves, to a processing chamber where the vacuum processing is performed,
• the gas supply unit comprising
• an air circuit that controls air to drive the plurality of air-driven valves, the air circuit comprising
• a plurality of three-position spring return center exhaust type five-port electromagnetic valves each having a solenoid coil and each coupled to one of a corresponding pair of the plurality of air-driven valves, each said three-position spring return center exhaust type five-port electromagnetic valve being configured to generate air to drive open one of said plurality of air-driven valves,
• wherein said plurality of pairs of normally closed air-driven valves comprises a first pair of normally closed air-driven valves consisting of a last stage valve and a disposable gas valve, and at least a second and third pair of normally closed air-driven valves, each of said second and third pairs of normally closed air-driven valves comprising a respective supply valve and a respective purge valve,
• wherein the air circuit is configured such that when a first air-driven valve of said first pair of the plurality of pairs of normally-closed air-driven valves is opened, a second air-driven valve of said first pair of normally-closed air-driven valves is maintained closed, and
• wherein the air circuit is further configured to prevent any air-driven valve of said second and third pairs of normally closed air-driven valves from opening unless one of said last stage valve and said disposable gas valve of said first pair of normally closed air-driven valves opens.