To provide a reduced pressure drying device used when a pattern is formed by the photolithography method, in which the state where a vacuum pump does not contribute to a reduced pressure process is eliminated during a carry-in operation and a hermetically-sealing operation and during an opening operation and a carry-out operation to improve process performance, and by which an influence to a coated film caused by a steep pressure reduction is suppressed, and various process conditions are set.

The device consists of a plurality of reduced pressure drying devices provided in parallel, includes a plurality of vacuum pumps P1 to P4 as vacuum pumps that reduce pressures in chambers 14-1 and 14-2. Each of the plurality of vacuum pumps is connected to each chamber of the plurality of reduced pressure drying devices via pipe arrangements 6-1 to 6-4 and bulbs B1 to B8. Pressure reduction using an arbitrary number of vacuum pumps is performed to each chamber.