To discriminate a polishing final point and finish polishing start properly by measuring the torque of at least one of a rotating shaft which rotates a polishing surface plate formed with a polishing pad and a rotating shaft which rotates an object to be polished and monitoring a progress status based on an integrated torque value.

A torque measuring mechanism 8 measures torque and transmits a torque measuring signal to a polishing progress status monitoring part 9. As the torque measuring mechanism 8, for example, electric power applied to the motor of a polishing surface plate rotation driving mechanism 7 is measured, and a device which calculates it from the electric power value and the rotational speed of the polishing surface plate 5, or an equivalent may be used. Where the rotational speed of a polishing surface plate 5 is fixed, the electric power may be used, left as it is. Torque measurement is made on the torque against the rotating shaft which drives the polishing surface plate 5, however, it may be made on the rotating shaft of a polishing disc 3 which rotates the object to be polished, and may be made on both of them.