An exposure apparatus has a projection optical system. The projection
optical system has a first optical element closest to an image plane
thereof and a second optical element which is second closest to the image
plane with respect to the first optical element. The first optical
element has a lower surface arranged opposite to a surface of a substrate
and an upper surface arranged opposite to the second optical element. A
space between the second optical element and the upper surface of the
first optical element is filled with a second liquid so that a liquid
immersion area is formed in an area of the upper surface, the area
including an area through which an exposure light beam passes. The
substrate is exposed by radiating the exposure light beam onto the
substrate through a first liquid on a side of the lower surface of the
first optical element and the second liquid on a side of the upper
surface. It is possible to avoid any deterioration of the exposure
accuracy caused by the pollution of the optical element, and to suppress
any enormous expansion of the liquid immersion area.