Patent ID: 8021210

Claim:
A polishing head having at least: an approximately discoid mid plate; a rubber film held by the mid plate, the rubber film covering at least a lower face portion and a side face portion of the mid plate; and an annular guide ring at a lower portion of a polishing head body, the annular guide ring being around a periphery of the rubber film; the polishing head in which there exists a first sealed space portion surrounded by the mid plate and the rubber film, a pressure of the first sealed space portion can be changed by a first pressure adjustment mechanism, a back face of a work is held on a lower face portion of the rubber film, and a surface of the work is brought into sliding contact with a polishing pad attached onto a turn table for performing polishing, wherein an end portion of the rubber film held by the mid plate is formed in O-ring shape, the mid plate is formed to be capable of vertically splitting in two pieces, the mid plate and the rubber film have a space at least throughout a whole surface of the lower face portion and the side face portion of the mid plate, and the rubber film is held by pinching the O-ring end portion of the rubber film between the split mid plate.