PURPOSE: To realize easy handling at the time of fabrication, assemblage and dismantling by directing the polarities of permanent magnets mounted on inner and outer rings in the circumferential direction thereby canceling the magnetic force functioning between the inner and outer rings of a magnet coupling.

CONSTITUTION: Permanent magnets 8, 11 mounted on inner and outer rings 3, 6 comprise magnetic bodies 14, 20 mounted rotatably in eight cylindrical holes made in tubular permeable bodies 9, 12 disposed, respectively, on the inner and outer surfaces of tubular magnetic bodies 7, 10 constituting the inner and outer rings 3, 6. A lever means for rotating the direction of the magnetic poles of the magnetic bodies 14, 20 is then coupled through a fulcrum and the tubular magnetic bodies 7, 10 of the inner and outer rings 3, 6 are provided, respectively, with means for guiding the operation of the lever means. N and S poles of the permanent magnets 8, 11 are directed in the circumferential direction to cause magnetic function between adjacent permanent magnets thus canceling magnetic forces functioning between the inner and outer rings. According to the constitution, fabrication, assemblage and dismantling can be carried out with no adverse effect of magnetic force resulting in easy handling.