Patent ID: 7282819

Claim:
A stage apparatus comprising: a movable member that moves at least in a first direction and a second direction; a mounting base supporting the movable member, and moving on a reference surface so as to cancel out a reaction force resulting from a movement of the movable member; and support means for supporting the mounting base above the reference surface, the support means including: (i) a first magnet unit disposed on said mounting base; (ii) a second magnet unit, disposed on the reference surface, said second magnet unit including a pair of permanent magnets, wherein said first magnet unit is disposed in a non-contact position between the pair of permanent magnets of said second magnet unit, with each of magnetic poles of said first magnet unit oriented opposed to like magnetic poles of said first and second permanent magnets; and area adjusting means that adjusts a facing area between the magnet of said first magnet unit and each of the magnets of said second magnet unit.