To provide a CMP (chemical mechanical polishing) device which polishes, based on the detection of a conditional changes during polishing work, by catching the changes in the abrasive which occurs during the polishing work.

The CMP device (polishing unit 1 or the like) applies polishing work on a wafer 5 through the abrasive supplied between a polishing pad 3 and the wafer 5, by turning relatively the polishing pad 3 and the wafer 5. The device is constituted so as to have an abrasive supplier 11 for supplying the abrasive employed for the polishing work, a viscosity detector 14 for measuring the viscosity and the amount of shearing of the abrasive supplied by the abrasive supplier 11, and a condition-monitoring unit 16 for detecting the conditional changes of the abrasive during the polishing work, from the detected viscosity and amount of shearing.