PURPOSE: To provide a manufacturing method of a semiconductor device, which enables satisfactory increase in carrier density near a PN-junction plane of a III-V compound semiconductor, and which particularly provides satisfactory tunnel junction property.

CONSTITUTION: In a manufacturing method of a semiconductor device for forming PN-junction of a III-V compound semiconductor layer by vapor phase growth, a first region of a predetermined thickness is doped with either one of first or second impurities as an acceptor or donor. A second region of a predetermined thickness is doped with the other one of the first or second impurities from near the center part in the thickness of the first region, so that the density of the donor is higher than that of the acceptor. Thus, PN- junction is formed.