To continuously perform rough cutting polishing, intermediate finish polishing and finish polishing in a series of process by single polishing media by arranging a work under a supply port of a polishing medium housing tank bottom part, and continuously supplying the polishing media of a polishing medium housing tank to a surface of the work while vibrating the work.

In a condition where an on-vehicle wheel W is rotated while vibrating it, polishing media 20, 20,... are naturally dropped toward a surface of the on-vehicle wheel W from a medium supply port 12 of a polishing medium housing tank 10. Since supply pressure to the on-vehicle wheel W is gradually reduced as the polishing media 20, 20,... reduce from the polishing medium housing tank 10, even if the single polishing media 20, 20,... are used, a surface of the on-vehicle wheel W can be polished in a rough cutting condition at the beginning when the supply pressure is strong, and intermediate finish polishing and finish polishing can be continuously performed on the surface of the on- vehicle wheel W according to a gradual reduction in the supply pressure of these polishing media 20, 20,....