PURPOSE: To perform a drying treatment on a wafer in a stable state in the simple structure, without being subjected to the restriction of the installation place and also, preventing damage to the wafer by fixing the wafer by one end part of the wafer retention pawls which are shifted on the recessed part of the chuck by a centrifugal force.

CONSTITUTION: A wafer 12 is housed in a recessed part 13 of a chuck 20 and thereafter, a chuck main body 11 is rotated. At this time, wafer retention pawls 16aW16c make bend end parts 17aW17c elongate outside on the recessed part 13 by the centrifugal force to accompany the turning force of the main body 11. A drying treatment of the wafer 12 is performed in a state that the wafer 12 is reliably held by the pinching action of the bent end arts 17aW17c and spacer pins 14. When the rotation of the main body 11 is stopped after the drying treatment, the wafer press pawls 16aW16c are returned to the prescribed positions on the main body 11 by the action of springs 19. Then, the wafer 12 is taken out of the recessed part 13.