| 摘要 |
PROBLEM TO BE SOLVED: To restrain lowering of throughput caused by treatment for detecting an optimum focus position of an observation optical system which observes a pattern or a mark of an original film by storing a maximum focus measurement value and an optimum focus position as proper data of an original film. SOLUTION: In a coordinate position of an alignment mark 4 on a reticle 2, it is judged whether or not automatic reticle focus measurement was performed in the past and an optimum focus position obtained then, and a maximum focus measurement value measured at an optimum focus position are stored. When an optimum focus position and a maximum focus measurement value measured at an optimum focus position are stored, a relay lens 11 of an observation optical system 13 is driven to an optimum focus position which is stored as data of each reticle. Focus measurement is carried out just once. |
