Patent ID: 8520184

Claim:
An exposure apparatus comprising: a projection optical system via which a substrate is exposed to an exposure beam through an immersion liquid; a liquid supply system including a supply channel fluidly connected to a space under the projection optical system, which supplies the immersion liquid; a first liquid recovery system including a recovery channel fluidly connected to the space which recovers the supplied immersion liquid from the space, the immersion liquid recovered from the space being disposed of without returning to the supply channel; a liquid immersion area forming member below which the substrate is moved during the exposure, and via which the first liquid recovery system recovers the immersion liquid from the space, the liquid immersion area forming member having an opening through which the exposure beam is projected; a first measuring system which measures at least one of a property and composition of the immersion liquid recovered from the space and discharged from the liquid immersion area forming member; and a controller which determines whether or not to perform a cleaning of the liquid immersion area forming member based on a measurement result of the first measuring system.