Patent attributes
A substrate processing apparatus includes: a substrate conveyance area; a substrate storage conveyance area; a substrate storage storing shelf; a first purge gas supply unit that supplies a purge gas into the substrate storage on the substrate storage storing shelf; an integrated flow rate acquiring unit that acquires an integrated flow rate of the purge gas supplied into the substrate storage; a transfer and placement unit; a second purge gas supply unit that supplies a purge gas into the substrate storage placed on the transfer and placement unit; a substrate transfer unit that transfers the substrate into the substrate conveyance area when the substrate storage is opened; and a controller that calculates an oxygen concentration within the substrate storage based on the integrated flow rate of the purge gas, and transfers the substrate to the substrate conveyance area when the oxygen concentration is a threshold value or less.