A bottom pole layer and a top pole layer respectively incorporate pole portion layers. Cross sections of the pole portion layers and a gap layer parallel to the top surface of a substrate are of the same shapes. The aggregate of the pole portion layers and the gap layer includes a first portion having a width W that defines the track width, and a second portion having a width greater than the width W of the first portion. L/W falls within a range of 2 to 5 inclusive, where L is the distance from a medium facing surface to the interface between the first portion and the second portion. S/(W.times.L) falls within a range of 5 to 40 inclusive, where S is the area of the cross section of the aggregate parallel to the top surface of the substrate.