Gate valve, substrate processing apparatus, and substrate processing method

The invention provides a gate valve, a substrate processing apparatus, and a substrate processing method capable of improving airtightness and cleanliness of a vacuum processing chamber and a vacuum preparation chamber. The gate valve connects the vacuum processing chamber and the vacuum preparation chamber in an openable and closable manner by abutting a surface on a side facing each of the vacuum processing chamber and the vacuum preparation chamber against an annular sealing member surrounding the entire circumference of a substrate inlet/outlet disposed facing each other of the vacuum processing chamber and the vacuum preparation chamber. Sealing flow paths are provided between sealing members provided so as to doubly surround the entire circumference of a substrate inlet/outlet of at least one of a vacuum processing chamber and a vacuum preparation chamber, and between other sealing members provided doubly inside/outside at one or more locations inside a gate valve. And a gas circulation flow path that i