Patent ID: 8520187

Claim:
A lithographic projection apparatus that projects a pattern from a patterning device onto a substrate using a projection system and having a liquid supply system that supplies a liquid to a first space between the projection system and the substrate, the apparatus comprising: a fluid removal system including a passage having an end opening that directly communicates with a second space in which fluid will be present, wherein the second space is in fluidic communication with the first space, the second space is disposed farther from an optical axis of the projection system than is the first space, liquid that flows from the first space to the second space subsequently flows from the second space into the passage through the end opening, the end opening faces downward, and when the liquid is present in the passage, substantially only liquid is removed from the second space to the passage through the end opening when liquid in the second space is adjacent the end opening but gas is not removed from the second space to the passage through the end opening when gas in the second space is adjacent the end opening.