A planar thin film magnetic head is disclosed wherein an axis of easy magnetization in the vicinity of a magnetic gap of a magnetic yoke is forcibly made coincident with the direction of a track width by a magnetic field due to current flowing in a conductor layer. Accordingly, even though the track width is small, a high magnetic permeability, low Barkhausen noise and linear responsiveness can be realized to thereby improve the sensitivity, output and linearity. In another aspect of the invention, a throat portion is eliminated from a thin film magnetic core forming a magnetic gap. The thin film magnetic core is configured such that a pair of magnetic members constituting the magnetic core are diverged from the magnetic gap so that a divergent angle .theta., of first opposite side edges of the magnetic members, from a direction of the gap length of the magnetic gap, is set to the range of 30.degree..ltoreq..theta..ltoreq.80.degree., and the magnetic members have second opposite side edges extending in substantially parallel to the direction of the gap length of the magnetic gap. Accordingly, even though a track width is reduced less than 10 .mu.m, adjoining crosstalk or off track crosstalk can be avoided to thereby realize low-noise and high quality reproduction and improve the operating characteristics.