To improve the separation performance of granules from game media by providing a game media passage opening downward at the downstream of the outlet of a polishing device that polishes while mixedly agitated with granules smaller than the game media and providing a vibration provision means that provides vibration to the passage.

By the rotation of a spiral 12, pachinko game balls (hereinafter called 'balls') that are transported upward while being polished by being mixed with pellets 16 and agitated are discharged onto a ball passage from the outlet 14 of a lift sending pipe 11. Some of the pellets discharged from the outlet 14 together with the balls drop into a hopper 18 through gaps of a plurality of rail members 20 and returned to the lift sending pipe 11 through a hose 19. On this occasion, with the vertical movement of the moving shaft 27 of an electromagnetic solenoid 26, a butting plate 28 contacts the upper ends of separators 24 in which holds allowing the passage of the balls are formed, and vibrates the rail members 20, and surely drops off the pellets 16 adhering to the surfaces of the balls into the hopper 18.