Abstract: A stage apparatus and method of mounting a substrate on a substrate holding surface of a substrate chuck in which a substrate is mounted in a Z-axis direction. The stage apparatus includes a movable stage, which is movable on an X-Y plane, a substrate stage mounted on the movable stage to be movable at least in a Z-axis direction, a substrate chuck which is arranged on the substrate stage for holding a substrate and a substrate support device, which is brought into contact with the substrate on the chuck and receives the substrate when the substrate stage moves in the Z-axis direction. The substrate support device includes a substrate supporting number arranged on the movable stage and the substrate stage has an opening through which the substrate supporting member can pass. A contact surface of the substrate chuck is located above a substrate contact surface of the substrate supporting member upon movement of the substrate stage.