Patent ID: 7826030

Claim:
A lithographic apparatus, comprising: a projection system configured to project a patterned radiation beam onto a target portion of a substrate; a liquid supply system configured to provide a liquid to a space between the projection system and a substrate; and a recycling system configured to collect liquid leaving the liquid supply system and to re-provide the liquid to the liquid supply system, the recycling system comprising two parallel liquid treatment units configured to treat the liquid, the parallel liquid treatment units arranged to treat different liquid such that there are two recycling paths for liquid from the liquid supply system through the recycling system back to the liquid supply system, wherein the two parallel liquid treatment units are configured to apply different treatments to the respective liquid such that, in use, one of the two parallel liquid treatment units treats a level or type of contaminant or both in the liquid that is different from a level or type of contaminant or both in the liquid treated by the other one of the two parallel liquid treatment units.