Patent ID: 7883582

Claim:
A vacuum processing apparatus comprising: a vacuum transfer chamber having a transfer unit for transferring a target object to and from an adjacent chamber, the inside of the vacuum transfer chamber being maintained at a depressurized state; a vacuum processing chamber, which is disposed adjacent to the vacuum transfer chamber, for performing a predetermined process on the target object under a reduced pressure; a gas exhaust unit for evacuating the vacuum transfer chamber; a purge gas supply unit for supplying a purge gas into the vacuum transfer chamber; and a control unit for controlling an internal pressure of the vacuum transfer chamber while monitoring whether or not a flow rate of the purge gas supplied into the vacuum transfer chamber from the purge gas supply unit is smaller than a lower limit of the flow rate, wherein the gas exhaust unit evacuates the vacuum transfer chamber at a constant gas exhaust rate so that the flow rate of the purge gas supplied into the vacuum transfer chamber corresponds to the internal pressure of the vacuum transfer chamber with a specific relationship, wherein the control unit is configured to change an internal pressure set value of the vacuum transfer chamber when the monitored flow rate of the purge gas is lower than the lower limit, and wherein the control unit is configured to control the internal pressure of the vacuum transfer chamber so that the internal pressure of the vacuum transfer chamber is set higher than that of the vacuum processing chamber.