PURPOSE: To polish the body to be polished of a gem decorative article, etc., going into fine part, easily and quickly.

CONSTITUTION: A strong magnetic material and non-magnetic material are mixed in the container contained with the body to be polished, a magnetic force generation device having an iron made rotating panel rotatable at high speed is faced to the bottom face of this container, a magnet is arranged on the center located on the above mentioned rotating panel, also four installation parts are provided at equal intervals along the peripheral end on the rotating panel, and a plate-like magnet of a opposite poles are arranged at one place or more among the four installation parts of the peripheral end, to the pole of the magnet arranged at the center located on the above mentioned rotating panel.