PURPOSE: To prevent a work from being dented and broken by filling a polishing vessel with a liquid, then charging a work into the vessel, and polishing the work after discharging the liquid.

CONSTITUTION: A discharge port 14a of the lower part of a polishing vessel 14 is closed, and water is filled in the polishing vessel 14. A mass comprising a work, a media and a compound is charged from a supply bucket 50 into the polishing vessel 14. A designated amount of mass is settled in the liquid to be accommodated in the polishing vessel 14. Subsequently, the discharge port 14a is opened to discharge the water. After discharging the water, the polishing vessel 14 is operated by a driving device 12, and a longitudinal shaft 11 is rotated to rotate a disc-like base plate 8 horizontally. Thus, the mass is repeatedly raised, turned and lowered along the inner peripheral wall of a liner 7 of a fixed cylinder by centrifugal force to perform polishing. Thus, the work is charged into a liquid so that shock at the time of charging can be lessened, and furthermore, as the mass is separated and slowly settled, the work can be prevented from being dented and broken.