| 摘要 |
PROBLEM TO BE SOLVED: To sample a laser gas directly at the installed place of an excimer laser and to decide whether there are impurities in the laser gas or not. SOLUTION: A gas exclusively sampling piping 3, connected to a laser gas feeding line L1 in the maintenance region of the excimer laser 1 for taking partly the laser gas, is provided. The gas sampling piping 3 has an open/close valve B1 halfway at the feeding line L1. In this case, the sampling piping 3 is joined to connection piping 13 of a sampling circuit SC, that includes a third open/close valve B3 at joining piping 13, a sampling container movably joined to an opened end of the joining piping 13, and first and second branch piping 15 and 16 branched through a fourth open/close valve B4 between the first third open/close valves B1 and B3. The first branch piping 15 is joined to a rare gas source via an open/close valve B5, and the second branch piping 16 is joined to the vacuum source via an open/close valve B6. |
