Pattern transfer can be performed with improved exposure accuracy, by
reducing the contamination caused by the attachment of a photosensitive
agent or the like on an optical member of a projection optical member or
the like. The pattern transfer onto a substrate W is performed after
cleaning the objective member OB disposed at a given position by a
cleaning device 8 at the time when pattern transfer is not performed, or
while making flow a gas in a space between the substrate W and the
optical member OB by a contamination protection device 98. Alternatively,
the optical member OB disposed at a given position is inspected for
contamination by a contamination inspection device 84 at the time when
pattern transfer is not performed, and the pattern transfer or the
cleaning or replacement of the optical member is performed based on the
result.