To form a highly accurate pattern while ensuring a wide exposure area in a projection exposure device.

The projection optical system 30 of the projection exposure device comprises a first lens group 32, a second lens group 34, a third lens group 36, and a fourth lens group 38. A polarization beam splitter 40 is arranged between the first lens group 32 and the second and third lens groups 34 and 36. The optical characteristic of the first lens group 32 is determined so that marginal light rays ML1 and ML2 from a point on the optical axis of a mask PM is made perpendicularly incident on the incident face of a polarization beam splitter 40.