Disclosed is a rotary device of a generator or motor which includes: a stator having a hollow portion formed at the inside thereof and a plurality of slots formed to wind coils therearound, each of the plurality of slots being skewed at a predetermined angle; a rotor shaft formed of a nonmagnetic material; a cylindrical rotor body adapted to axially rotate together with the rotor shaft; a plurality of N-polar and S-polar permanent magnet groups insertedly coupled radially along the outside of the center portion of the rotor body in an alternating arrangement; a plurality of magnetic flux-increasing magnets insertedly coupled along the inside of the rotor body and arranged on the lines of magnetic force formed by the N-polar and S-polar permanent magnet groups, for increasing magnetic flux; and a rotor adapted to be rotatably inserted into the hollow portion of the stator.