Patent ID: 7115026

Claim:
A polishing apparatus, comprising: a lower polishing plate; an upper polishing plate being relatively moved with respect to said lower polishing plate so as to polish a work piece clamped between said lower polishing plate and upper polishing plate; and a holding mechanism for holding said upper polishing plate, wherein said holding mechanism includes: an inner member; an outer member having an upper open end and a lower open end, said outer member accommodating said inner member; a first elastic member being made of an elastic material and formed into a ring-shape with a prescribed width, said first elastic member connecting an upper part of said inner member and an upper part of said outer member and closing the upper open end of said outer member; a second elastic member being made of an elastic material and formed into a ring-shape with a prescribed width, said second elastic member connecting a lower part of said inner member and a lower part of said outer member and closing the lower open end of said outer member; a first closed space being enclosed by an outer face of said inner member, an inner face of said outer member, said first elastic member and said second elastic member; and a fluid supply section supplying a pressurized fluid into said first closed space, one of said inner member and said outer member is connected to a rotary drive unit, the other is connected to said upper polishing plate, and said upper polishing plate is rotated in a horizontal plane, by said rotary drive unit, with said inner member and said outer member, and a pressure difference between a first pressing force pressing said outer member or said inner member upward and a second pressing force pressing said outer member or said inner member downward, which is produced in said first closed space by supplying the compressed fluid into and discharging the same from said first closed space, is adjusted so as to adjust a third pressing force of said upper polishing plate, which presses the work piece, while polishing the work piece.