PURPOSE: To prevent medals from remaining in a polishing device by a method where a abrasive material separating drum which has the pivotal axis in an approx. horizontal direction, and on the peripheral surface of which abrasive material passing through holes are formed, is provided to be rotatable with a motor, under a cylindrical pipe.

CONSTITUTION: An abrasive material drops from abrasive material passing through holes 10b, and polished medals 7 only are recovered by a medal recovering passage 12. After the completion of a polishing work, spiral plates 3a, 3b in a cylindrical pipe 1 are reversed, and at the same time, a shutter 26 is opened while a abrasive material separating drum 18 is being turned. Then, the abrasive material and medals remaining in the cylindrical pipe 1 are fed in the opposite direction, and fed to the inside of the abrasive material separating drum 18 by a transfer passage 27 in order. Since a spiral protruding strap 14 turns in the abrasive material separating drum 18, the medals, together with the abrasive material, are fed in the advancing direction of the spiral, and the abrasive material drops from abrasive material passing through holes 13 on the drum peripheral surface, on the way. Then, the medals only are fed out from an outlet 25 at the other end side by a passage 33.