Abstract: A lithographic apparatus has an assembly to exchange optical elements in a pupil plane of its projection system. The optical elements may be pupil filters and may conform to the physical dimensions specified for a reticle standard, e.g. having sides substantially equal to 5, 6 or 9 inches.

Abstract: Embodiments of the invention relates to a substrate handler for handling a substrate, including a conditioning device for conditioning the substrate. In an embodiment, the substrate handler includes a displacing device configured to displace the substrate in a direction substantially parallel to the support surface, wherein the displacing device is configured to displace the substrate during the conditioning process from one conditioning position to one or more other conditioning positions. According to another embodiment of the invention, the substrate handler includes a float device for providing an air bed above a support surface of the substrate handler, the substrate handler being configured to support the substrate on an air bed during conditioning of the substrate.