To provide a polishing head capable of achieving a polished surface with excellent flatness without generating uneven deformation on a backing pad.

A top ring 6 is fixed on an end of a main shaft 4 through a top block 5. A recessed part 7 is provided in a center of a top surface of the top ring 6 and plural through-holes 8 are formed on a bottom surface thereof so as to penetrate along vertical direction. A wafer 1 is suctioned to a lower surface of the top ring 6 through the backing pad 2. A piston 11 is accommodated in the top block 5. A pressing plate 12 is installed on an end of the piston 11. When polishing the wafer 1, the piston 11 is moved forward to the limit and the pressing plate 12 is adhered to a bottom surface of the recessed part 7 so as to close the each through-hole 8. When releasing the wafer 1, the piston 11 is moved backward to the limit and pressurized air is delivered from the each through-hole 8 to apply a pressure to the wafer 1 from a reverse side.