There is provided a thin film magnetic head, with letting a distance of a
portion, where a width of a track portion in an upper magnetic pole
changes, from a flying plane from a medium be Ly, and letting a distance
of a portion, where a distance between right and left of a surface
portion in a lower magnetic pole in a track width direction is wider than
the width of the upper magnetic pole in the track width direction, from
the flying plane from a medium be Tp, by creating a thin film magnetic
head that is equipped with a recording head that has a relation of
Tp.ltoreq.Ly, it becomes possible to reduce a needless leakage magnetic
field in the track width direction with securing magnetic field strength.