Patent ID: 7908995

Claim:
A stage apparatus comprising: a stage over which a rectangular substrate is to be transferred; and a levitation mechanism which levitates the rectangular substrate over the stage, the rectangular substrate which is levitated over the stage being transferred such that a pair of sides of the rectangular substrate are substantially parallel to a transfer direction and the other pair of sides of the rectangular substrate are substantially perpendicular to the transfer direction, wherein the stage includes a plurality of gas spray ports to spray a gas and a plurality of suction ports to attract the rectangular substrate by suction, the levitation mechanism includes a suction mechanism which takes in air through the suction ports and a gas spray mechanism which sprays the gas through the gas spray ports, and serves to levitate the rectangular substrate at a predetermined height from a surface of the stage in a substantially horizontal posture by means of suction of the suction mechanism through said plurality of suction ports and gas spray of the gas spray mechanism through said plurality of gas spray ports, and said plurality of suction ports are arranged on the stage at a predetermined pitch in a predetermined direction shifting by a predetermined angle from a perpendicular direction perpendicular to the transfer direction and are arranged not to be aligned side by side in the perpendicular direction, such that, when the rectangular substrate is being transferred over the stage, the rectangular substrate is prevented from receiving sharp variations in suction pressure applied thereto.