Abstract: A lithographic apparatus includes an illumination system for providing a beam of radiation. The lithographic apparatus further includes: a support structure for supporting patterning device, the patterning device serving to impart the beam with a pattern in its cross-section; a substrate table for holding a substrate; and a projection system for projecting the patterned beam onto a target portion of the substrate. The lithographic apparatus includes a vacuum system in which at least the illumination system and the substrate table are present. The vacuum system includes at least two separate vacuum modules. A first vacuum module includes at least the projection system and/or the illumination system. A second vacuum module includes the substrate table. At least two of the vacuum modules are connected to each other via a closable connection.