PURPOSE: To provide a barrel polishing machine which can respectively generate a rotational magnetic field or a variational magnetic field due to alternating current by two sorts of iron cores with windings so as to polish parts more strongly and in good quality, and the polishing method therefor.

CONSTITUTION: Iron cores 8 with windings 7 are arranged on the outer bottom face and the side face of a vessel 4. Electric current is carried in these windings 7 so as to generate a rotational magnetic field in the vessel. Electromagnetic force is given to media 1 having magnetism in the vessel by the magnetic field, so as to move the media 1. Parts 2 are polished by relative motion between the media and the parts 2 in the vessel.