A scanning type exposure apparatus includes a projection optical system which
projects
a pattern of a reticle onto a wafer, which is held by a wafer chuck, a scanning
stage system which scanningly moves the reticle and the wafer synchronously with
respect the projection optical system, and an inspection system which automatically
inspects influence of particles on at least one of the wafer and on the wafer chuck.
The inspection system includes a focus detector which measures a focus state of
the wafer and a calculator which calculates outputs of the focus detector.
