PURPOSE: To enable the manufacture of a magnetic head having high mechanical reliability without deterioration of magnetic properties even if a glass fusion- bonding process is employed by setting the number N of outer electrons of elements which form magnetically soft amorphous material and mean outer electrons obtained from atomic density (at.%) to N≤8.3.

CONSTITUTION: A magnetically soft amorphous thin film formed by adding at least one type or more of metal elements of Zr, Hf, Nb, Ta, W, Mo, V, Ti, Re and Ru or metalloid element of B, C, Si and P to Co of main content of various composition is formed on a glass substrate by a high frequency magnetron sputtering method. The number N of mean outer electrons obtained from the outer electron number of the elements which form the magnetically soft amorphous material and an atomic density (at.%) is set to N≤8.3. If the number N is less than 8.3, crystallizing temperature T is 520°C or higher, and even if the same heat treatment as glass fusion-bonding process is executed, the magnetic property of the magnetic material is not deteriorated at all but can sufficiently endure against the heat treatment at the glass fusion-bonding time.