At both end portions of at least a soft magnetic layer of a magneto-resistive effect film, a pair of bias magnetic field applying layers are disposed for applying a longitudinal bias magnetic field to the soft magnetic layer via magnetic underlayers. Further, mutual lattice point-to-point distances in the plane where each magnetic underlayer and the corresponding bias magnetic field applying layer are mated, are substantially equalized to each other. Therefore, a coercive force Hc in an in-plane direction (direction parallel to a film surface) of each bias magnetic field applying layer can be maintained at a high level so that even when further gap narrowing or track narrowing is aimed, the bias magnetic field applying layers can act to apply an effective bias magnetic field, i.e. can act to suppress occurrence of the Barkhausen noise.