Lithographic projection apparatus

摘要

A lithographic projection apparatus comprising: an illumination system LA, EX, IN, CO for supplying a projection beam of radiation PB; a first object table MT for holding a mask MA; a second object table WT provided with a support surface for supporting and holding a substrate W at its backside surface; and, a projection system PL for imaging an irradiated portion of the mask MA onto a target portion of the substrate W, characterized in that the apparatus comprises contamination detection means constructed and arranged to detect the presence of contamination on one or both of the support surface and the substrate backside surface. <IMAGE>