Patent ID: 8235001

Claim:
A substrate processing apparatus comprising: a processing chamber in which a substrate is processed; a processing gas feeding line that feeds a processing gas into said processing chamber; an inert gas feeding line that feeds an inert gas into said processing chamber; an inert gas vent line provided in said inert gas feeding line, which exhausts said inert gas fed into said inert gas feeding line without feeding said inert gas into said processing chamber; a first valve provided in said inert gas feeding line, on a downstream side of a part where said inert gas vent line is provided in said inert gas feeding line; a second valve provided in said inert gas vent line; a third valve provided in said processing gas feeding line; an exhaust line that exhausts an inside of said processing chamber; and a main controller that is configured to control said first, second and third valves so that: processing is applied to said substrate by alternately repeating feed of said processing gas into said processing chamber through said processing gas feeding line, and feed of said inert gas into said processing chamber through said inert gas feeding line, said inert gas fed into said inert gas feeding line is exhausted through said inert gas vent line when said inert gas is not fed into said processing chamber through said inert gas feeding line; and a flow of said inert gas fed into said inert gas feeding line is switched from said flow toward said inert gas vent line to said flow toward said inside of said processing chamber when said inert gas is fed into said processing chamber through said inert gas feeding line.