To provide a manufacturing method of a projection aligner that can be manufactured while restraining the adhesion of chemical contaminants to members at low costs.

The manufacturing method for the projection aligner comprising a plurality of subsystems includes: a process S1 for manufacturing the members; a process S2 for washing the members; a process S3 for storing the washed members in a chemically cleaned storage container; a process S4 for assembling the members stored in the storage container as the subsystems inside a chemically cleaned chemical clean booth; a process 5 for storing the assembled subsystems in the storage container; and a process S6 for assembling the plurality of subsystems stored in the storage container to form the projection aligner.