A magnetization reversal method is disclosed in which an external magnetic field is applied to a magnetoresistive film requiring a strong magnetic film for reversal. A weak magnetic field is applied when magnetically coupled perpendicular magnetic films are used in which the magnetoresistive film has a structure wherein a nonmagnetic film is placed between magnetic films with an easy axis of magnetization along a perpendicular direction to a film plane, and in which said external magnetic field is comprised of magnetic fields from a plurality of directions including a direction of easy magnetization of the magnetic films.