PURPOSE: To miniaturize an apparatus and lower the running cost based on recovery and repeating use of a polishing material by composing two polishing frames mutually separately and connecting an air transporting route of a rice polishing frame to a separation cyclone of another polishing frame.

CONSTITUTION: In a rice-polishing frame, a polished rice grain tank and a polishing material tank are installed and, at the same time, a rice polishing part to polish rice by mixing rice grains to be polished with a polishing material together and a separating part to separate the polished rice grains after polished and the polishing material are also installed. Meanwhile, in a polishing frame which is installed separately from the rice polishing frame, a separation cyclone 34 to which the polishing material separated in the separating part of the rice polishing frame is supplied through an air transporting route 28 and a storage tank to store the separated polishing material and a supplying tank 47 to store a new polishing material are installed. After the recovered polishing material in the storage tank 35 and the new polishing material in the supplying tank 47 are mixed in a mixing part, the resultant polishing material is led to the polishing material tank in the rice polishing frame through a second air transporting route.