FIG. 6B to FIG. 9B are cross sections of the pole portion each parallel to the air bearing surface. [0070] In the manufacturing method, as shown in FIG. 6A and FIG. 6B, an insulating layer 2 made of an insulating material such as alumina (Al2O3) or silicon dioxide (SiO2) whose thickness is 1 to 20 ??m, for example, is formed through sputtering, for example, on a substrate 1 made of a ceramic mater