| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent an invasion of a disturbance of an air supply line into an air cylinder for compensating an own weight. SOLUTION: A Z-stage 1 for holding a wafer or the like supports its own weight by air cylinders 3a to 3c, and vertically moves to focus or the like via linear motors 4a to 4c. In order to avoid the disturbance due to a pressure change of a pressure source of the air supply line, characteristic variations of air regulators 5a to 5c, solenoid valves 6a to 6c are temporarily closed to cut the air supply line.</p> |
