PURPOSE: To increase a work speed by separately controlling a polishing pressure and grinding speed to the media inside a barrel tank.

CONSTITUTION: A revolving body (1) rotating on the shaft center and plural barrel tanks (21, 22, 23) rotating with a rotating shaft being provided on the concentric circle periphery located on the above revolving body, are provided, and a 1st rotation means (3) rotating the above revolving body (1) and 2nd rotation means (51, 52, 53) revolving the 1st rotation means (3) rotating the above revolving body (1) and the above barrel tank are provided, and the grinding pressure is made to be controlled by the above 1st rotation means and the grinding speed by the 2nd rotation means independently respectively. The grinding pressure and grinding speed can be controlled freely individually by the 1st rotation means and 2nd rotation means, therefore the work speed can be improved and also a peculiar effect easily capable of the optimum work corresponding to the work conditions of a rough grinding, finishing grind, etc., and the kind, etc., of a work is achieved fruitfully.