PURPOSE: To make it possible to rapidly damp vibration of an article mounting stage upon stopping of the latter, by storing a nonmagnetic movable member to which the stage is provided, in a container filled with magnetic fluid to move the stage in one unit body.

CONSTITUTION: A movable member 14 stably floats in magnetic fluid 17 in a container 16 due to the magnetic fields of magnets 15 attached to the side and bottom surfaces thereof. When a shaft 12 supported by a seal shaft bearing 11 is moved back and forth, the movable member 14 is moved in the same directions to move a stage 13 together therewith. When a drive system coupled with the shaft 12 is stopped, centering force effected on the right and left walls of the container 16 with respect to the back and forth directions and the viscosity of the magnetic fluid 17 allow deflection and vibration of the stage to be rapidly damped. Accordingly, it is possible to provide a movable to which lower vibration is transmitted from the outside.