In a thin film magnetic writing head structure, a high permeability layer is arranged parallel to the lateral face of a pole piece which is situated in the downstream direction of movement of the magnetic record carrier under the head airgap. Said high permeability layer is magnetostatically de-coupled from the pole piece. This arrangement guides the zero magnetic field lines from the head along the frontal plane of the pole piece and along the lateral face of said piece, thereby drastically reducing the action of de-magnetizing components of the writing flux on the record.