| 摘要 |
PROBLEM TO BE SOLVED: To always detect the position of a photosensitive substrate with a stable accuracy by covering at least a part of an alignment means for detecting the position of this substrate at specified air-tightness and controlling the temp. of a part of a gas. SOLUTION: An alignment system (position-detecting means) is composed of members at least among which are sensitive to heat are housed in an enclosure means 42. When the ambient temp. of detecting means 1-9 in the enclosure means 42 rises during the repeating of the position detecting operation in a photosensitive substrate W, a temp. control means 44 controls the air warmed in the enclosure means 42 to avoid excessive temp. rise around the detecting means 1-9, thus keeping ambient temp. of the detecting means 1-9 const. This ensures a stable pattern detection. |
