A lithographic apparatus comprising: a positioning stage (WT); an isolation frame (300); a projection system (PS), comprising a first frame (210); a second frame (220); a supporting frame (10) for supporting the positioning stage; a first vibration isolation system (250) and a second vibration isolation system (270), wherein the supporting frame and the first frame are coupled via the first vibration isolation system; a stage position measurement system (400) to determine directly the position of a stage reference of an element of the positioning stage in one or more degrees of freedom with respect to an isolation frame reference of an element of the isolation frame; and wherein the first frame and the isolation frame are coupled via the second vibration isolation system.