A pole layer incorporates a track width defining portion and a wide
portion. The track width defining portion has an end face that is located
in the medium facing surface and that defines the track width. The
maximum width of the wide portion is greater than the track width and
equal to or greater than the length of the wide portion taken in the
direction orthogonal to the medium facing surface. When the coil is
generating no magnetic field, in the end face of the track width defining
portion, there exist first and second regions in which the directions of
components of magnetization orthogonal to the medium facing surface are
opposite.