PURPOSE: To easily perform the fitting and removing of a barrel tank by fitting the barrel tank to a motor fitting cylinder freely detachably.

CONSTITUTION: The vibration caused by the operation of a vibration motor 8 is transmitted to a barrel tank 1 and the material to be polished is subjected to polishing by vibrating the polishing material and the material to be polished of the long-sized pipe part 3 of the barrel tank 1 inside with spirally moving them in a specified direction. In the case of replacing the barrel tank 1 due to the deterioration of the barrel tank 1 and the change of polishing conditions, the screwing of a bolt 12 and nut 13 is released and the barrel tank 1 is pulled out of a motor fitting cylinder 5. The barrel tank is thus removed and replaced with a new one.