PURPOSE: To prevent static accuracy from lowering and a dynamic posture accuracy from deteriorating, by guiding the vertical direction of a Y stage by a surface plate, the lateral direction by the fixed guide arranged on the surface plate, and making the guide in the vertical direction of an X stage by the surface plate and the guide in the lateral direction as one face of the Y stage side face.

CONSTITUTION: A surface plate is a reference face at its upper face and a fixed guide 2 becomes reference at its side face. A Y stage 4 is floated from a surface plate 1 by supplying air to a static pressure air bearing, and moved along the fixed guide 2 by two actuators 7a, 7b. Also, an X stage 5 is floated from the surface plate 1 by supplying air to the static pressure air bearing, and moved in an X direction by a driving actuator 8 with the one face of the side face of the Y stage 4 as the guide. Thus, both of the guides in the vertical direction of the X stage and Y stage are executed by the surface plate, no moving load is generated on the stage of the counter part side even in case of the X or Y stage being moved, and the static posture accuracy can be held well.