PURPOSE: To correctly arrange a disc at a predetermined position even when a robot hand is positionally controlled with more or less errors.

CONSTITUTION: A clamp base body 10 has a base 42 and a tower part 44 standing vertically from the base. A cap 12 has a central opening into which the tower part of the base body is inserted. The cap 12 is arranged on the clamp base body with a recessed part thereof at the side opposite to the clamp base body. A disc guide part 16 has an inclined part, 54 which is slidably fitted in the cap with pressure at an end of the tower part to guide a central opening of a disc. In order to dispose a disc 100, a robot hand once presses the disc guide part by a projecting part, and the disc guide part is fitted in the central opening of the disc while being guided by the inclined part when moving upward. The disc is accordingly arranged at a predetermined position.