A longitudinal bias magnetic field control layer applies a counter bias
magnetic field to a soft magnetic layer that is antiparallel (in opposite
direction) to a longitudinal bias magnetic field. A magnitude of the
counter bias magnetic field applied to the soft magnetic layer by the
longitudinal bias magnetic field control layer is set smaller than that
of the longitudinal bias magnetic field at a track center portion of the
soft magnetic layer applied by a pair of bias magnetic field applying
layers. A substantial longitudinal bias magnetic field is substantially
applied to the soft magnetic layer in the same direction as that of the
longitudinal bias magnetic field, and a magnitude of the substantial
longitudinal bias magnetic field is maximum at both end portions of the
soft magnetic layer and is weakened at the center portion of the soft
magnetic layer.