A thin-film magnetic head including a main magnetic pole layer having a magnetic pole end part on a side of a medium-opposing surface opposing a recording medium; a write shield layer opposing the magnetic pole end part to form a recording gap layer on the medium-opposing surface side; a thin-film coil wound about the write shield layer or the main magnetic pole layer; and a base insulating layer formed with a magnetic pole forming depression, including a very narrow groove defining a form of the magnetic pole end part and a main depression integrally extending from an end part of the very narrow groove remote from the medium-opposing surface. A stepped part is formed at a boundary between a bottom face of the main depression and a bottom face of the very narrow groove. The main magnetic pole layer is the only magnetically functional layer in the depression.