摘要:
A plurality of airtight chambers are connected through blocking means, which can communicate or shut off the chambers, and at least one of the airtight chambers is used as a processing chamber. One of the adjacent airtight chambers is replaced by a replacement gas, and the replacement gas is supplied to the other of the adjacent airtight chambers. When pressure difference or pressure in the two adjacent airtight chambers is below a predetermined value, the adjacent two airtight chambers are communicated, and pressure in the two airtight chambers is equalized.