A protrusion 24 having a width Lpfw equal to or somewhat larger than a track width Tw and protruding to the air bearing surface is provided on a lower magnetic pole 5 or lower magnetic pole front end layer 19. The lower magnetic pole 5 or the lower magnetic pole front end layer 19 other than the protrusion is retracted by Lpfd from the air bearing surface 15. With the constitution, since the upper end surface 23 of the lower magnetic pole 5 or the lower magnetic pole to end layer 19 that generates the leakage magnetic fields in the off-track portions is not exposed to the air bearing surface 15, the leakage magnetic fields Hxz in the off-track portions can be decreased greatly.