A polishing apparatus makes it possible to accurately detect the temperature of a workpiece during polishing and to perform polishing end point determination on the basis of this detected temperature. The polishing apparatus polishes irregularities in a surface of a workpiece such as for example a semiconductor wafer to a flat and mirror-like finish. A top ring holding a semiconductor wafer is provided with a temperature sensor. Frictional heat generated in the semiconductor wafer by polishing is detected by the temperature sensor, and a polishing end point is determined on the basis of the detected temperature.