A head chip of a magnetic head is produced by a method in which magnetic core half blocks, each having plural track width delimiting grooves on its major surface and having a magnetic metal film of a soft magnetic metal material formed on the major surface, are abutted to each other with a gap material in-between to form a magnetic head block which is then sliced to give plural head chips for the magnetic head. Each track width delimiting groove is polygonally-shaped in cross-section and has at least two bends. This enables suppression of cracks of exfoliation of the magnetic metal film otherwise caused in the magnetic core during its fabrication to improve product yield and operational reliability.