| 摘要 |
PROBLEM TO BE SOLVED: To prevent exposure shot deviation by distortion of a surface plate by adjusting a thrust of each air mount based on the output of a manometer and providing a vibration removal table control system for replacing the thrust of an actuator. SOLUTION: An actuator 4A generates a thrust in +Z direction for holding the holizontality of a column 3 and when it is detected that an air mount 5A consequently requires the thrust in the +Z direction, an air mount control part feeds an air pressure to the air mount 5A to expand the thrust in the +Z direction. The thrust is measured based on the internal pressure of the air mount 5A by a manometer, a feed system pipe is closed at a time of its reaching an allowable value of the target value so that the thrust replacement in the +Z direction by the air mount 5A is completed. The thrust of each actuator 4A in a corner is thus separately replaced by each air mount 5A in the corner so that the strain of the column 3 can be prevented, support parts of a projection optical system PL and position sensors 19a-c are prevented from being bent, and the exposition shot deviation can be prevented.
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