To provide a chemical mechanical polishing method for improving productivity without sacrificing flatness of a wafer, while using an existing polishing device.

Polishing is performed, while supplying abrasive material 12 between the wafer W and abrasive cloth 10 (a first polishing stage). Polishing is performed by increasing viscosity of the abrasive material 12 (a second polishing stage), while continuing a relative motion of the waver W and the abrasive cloth 10. As a result, a gap of the wafer W and the abrasive cloth 10 is expanded to reduce ripple.