To enable the surface of a chuck plate to be formed of the same member and made smooth and free from irregularities by preventing a non-permeable member from being exposed on the surface of the chuck plate.
The universal chuck is equipped with the disk-shaped chuck plate 1 that attracts a semiconductor wafer W to its upper surface by vacuum suction, and a cup-shaped chuck holder 2 that is engaged with the chuck plate 1. The chuck holder 2 is formed of non-permeable member, a fluid circulating shaft 3 is provided to the chuck holder 2, the chuck plate 1 is formed of a permeable member, an annular U-shaped groove 1a is cut on the lower surface of the chuck plate 1 at a size switching position, and a non-permeable ring member 4 is fit into the U-shaped groove 1a.
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TOYOSHIMA MASAYUKI
NAGATSUMA TADAHIRO
TANKEN SEAL SEIKO CO LTD