To provide a spin valve magnetoresistive effect device in which the magnetizing direction of a ferromagnetic fixed layer is easily changed by performing a heat treatment at Curie temperature or higher of a ferromagnetic free layer or at least the blocking temperature of an antiferromagnetic layer while applying a magnetic field in an orthogonal direction to the magnetizing direction of the ferromagnetic free layer and after that performing a cooling operation.

A reciprocating movement of a substrate 2 is started in the orthogonal direction to direction F1 of a magnetic field formed by first and second magnets. A ferromagnetic free layer 4 is laminated on the substrate 2, and after that, a spacer layer 5 is laminated. Subsequently, the reciprocating movement of the substrate 2 is stopped and a ferromagnetic fixed layer 6 and an antiferromagnetic layer 7 are sequentially laminated. The substrate 2 is arranged so that the direction F1 of the magnetic field formed by a first magnetic 12c having the N pole and a second magnet 13c having the S pole which are arranged so as to face each other orthogonally crosses a magnetizing direction 9 of the ferromagnetic free layer 4. A heat treatment is performed at least the blocking temperature of the antiferromagnetic layer 7, and self-cooling is executed.