摘要 |
A stage device for use in a vacuum includes a frame-shaped movable stage having a sample mounting surface, a fixed stage surrounded by the movable stage, an air bearing to float the movable stage by supplying gas to a gap between the stages, a pressure regulator to regulate a pressure of the gas, a differential pumping portion to prevent the gas from flowing outside the gap, and a controller. The controller moves the movable stage within a predetermined range under a pressure in the differential pumping portion set equal to that for movable stage in use when setting a floating height of the movable stage lower than that for movable stage in use, and under the pressure in the differential pumping portion set higher than that for movable stage in use when setting the floating height of the movable stage equal to that for movable stage in use. |