Patent ID: 8027019

Claim:
A lithographic apparatus, comprising: a substrate table constructed to hold a substrate; a liquid supply system configured to provide a liquid to a space between an object on the substrate table and a projection system; and a drain in the substrate table configured to contain liquid which leaks, in use, between an edge of the object and the substrate table, the drain comprising a chamber which is open to a top surface of the substrate table via a gap, the gap extending, in use, around the periphery of the object and a straight vertical path leads from outside of the substrate table and above the object, through the gap into the chamber, wherein, in use, pressure of gas in the drain is maintained to be substantially equal to ambient pressure of gas above the substrate table such that, in the absence of a flow of gas supplied above the object, there is substantially no flow of gas into the drain through between the edge of the object and the substrate table, and wherein faces which define the gap and face each other across the gap are convex such that the gap narrows in a middle portion.