To stably obtain an n-type or p-type boron-phosphide based semiconductor layer with precisely controlled carrier density by adding n-type or p-type impurities when the boron-phosphide based semiconductor layer is formed by a vapor-phase growing means.

In a state wherein boron occupying holes of phosphorus is present higher than the atom density of phosphorus occupying holes of boron in an undoped state, p-type impurities of a group II or IV group element are added to obtain a boron-phosphide based compound semiconductor layer. In a state wherein phosphorus occupying holes of boron is present higher than the atom density of boron occupying holes of phosphorus of boron in the undoped state, n-type impurities of a group IV or VI element to obtain an n-type boron-phosphide based compound semiconductor layer.