PURPOSE: To prevent a surface plate from its motion by reaction force, when a moving bed is driven, by providing, between a fixed part and the surface plate, a lock mechanism energized by a signal from a moving bed control device.

CONSTITUTION: A surface plate 3 is mounted onto a fixed part 1 through a vibration remover device 2, and the surface plate 3 mounts to its upper a y- moving bed 4 movable in a direction (y) by a guide mechanism 5 and to the upper of the bed 4 an x-moving bed 6 movable in a direction (x). While both the moving beds 4, 6 are driven by driving gears 7, 8, providing x, y lock mechanisms 1001, 1002 between the fixed part 1 and the surface plate 3 through a mounting member 9, and both the lock mechanisms 1001, 1002 are energized and locked by an excitation device with a moving bed control device receiving a drive signal of the moving bed. Accordingly, the surface plate 3 is prevented from performing its motion by reaction force when the moving beds 4, 6 are driven, and normally the vibration removing device 2 functions with an equipment possible to improve its accuracy.