To provide a polishing device which has a measuring means capable of measuring both values indicative of a surface shape and viscoelastic characteristics of a polishing pad in an actually used state during a polishing procedure.

The CMP (chemical mechanical polishing) device polishes a wafer by abutting the wafer on a polishing surface 27s of the polishing pad 27, and relatively moving the former and the latter with respect to each other. The CMP device is provided with: a pad shape measuring device having a main sensor 65 and a sub-sensor 66 for measuring a distance between the polishing surface 27s of the polishing pad 27 and a reference surface 62s to measure the surface shape of the polishing surface 27s of the polishing pad 27; and a pressure applying device pressed to the polishing surface 27s of the polishing pad 27 to apply a pressing load. Then the deformation volume generated in the polishing surface 27s of the polishing pad 27 is measured by the pressing load of the pressure loading device by using the main sensor 65 and the sub-sensor 66 to determine whether or not the deformation volume is within a referential range.