Projection exposure apparatus, and device manufacturing method which compensate for a change in optical performance of a projection optical system

摘要

A projection exposure apparatus includes a projection optical system with a barrel, a pressure measuring device disposed inside and/or outside the barrel, and a device for estimating a change in pressure in accordance with an output of the pressure measuring device and for compensating for a change in optical performance of the projection optical system due to the change in pressure, in accordance with the estimation.