A carrier comprising a disk-shaped body portion having fluid circulation holes, a ring-shaped diaphragm portion expanding outward from the outer peripheral surface of the body portion and having pliability, a ring-shaped edge portion projecting at least downward from an outer edge portion of the diaphragm portion and having an inner diameter of at least an outer diameter of a work piece, a pliable sheet having an outer peripheral portion affixed air tightly to a bottom end portion of said edge portion, the back surface of the sheet defining a single pressure chamber communicating with the fluid circulation holes, and a ring-shaped member surrounding the work piece affixed to the bottom surface of the sheet.