Patent ID: 8823918

Claim:
An immersion lithographic apparatus, comprising: an immersion liquid supply system to provide immersion liquid via an immersion liquid inlet; a projection system to project a beam of radiation through the immersion liquid onto a radiation-sensitive substrate; an inlet configured to introduce a cleaning fluid of a different material than the immersion liquid into a space, a surface to be cleaned at least in part defining the space, the inlet connected to a first opening connected or connectable to a cleaning fluid supply; and a liquid seal configured to seal around at least part of the space to hinder fluid surrounding the space from entering the space, wherein the liquid seal comprises a seal inlet configured to supply liquid of a different material than the cleaning fluid when there is cleaning fluid in the space, the seal inlet connected to a second opening connected or connectable to a supply of the liquid of the different material than the cleaning fluid, wherein the inlet or the seal inlet is different from the immersion liquid inlet.