In a magnetic head in which first and second core halves are disposed on the entry and leaving sides of a magnetic recording medium, respectively, one of the first and second core halves is provided with a first edge for limiting a data track width and second edges which are disposed on both sides of the first edge and are inclined by a first angle with respect to the first edge. The other core half is provided with a third edge which is opposed to the first edge and is equal in length to the first edge. The other core half is also provided with fourth edges disposed on both sides of the third edge and inclined by a second angle with respect to the third edge. The data recording is made in the magnetic field between the first and third edges. Furthermore, the recording is made on both sides of the data track by the magnetic fields between the second and fourth edges so that erasure of old data can still occur despite deviation of the positions of the new and old data tracks. On both sides, data which has an azimuth with respect to the data recorded on the data track is not reproduced and there is no adverse effect.