PURPOSE: To selectively make an epitaxial growth by a laser irradiation when a compound semiconductor is manufactured by an organic metal vapor deposition method.

CONSTITUTION: A mixed gas of trimethyl gallium 5, arsine 16 and others is introduced into a reaction chamber 31 as a material gas. A laser light 47 oscillated by an Ar laser oscillator 41 is converged by an objective lens 45 and irradiated onto a semiconductor substrate 34. The material gas is cracked by the heat generated by the laser light or by the photochemical reaction, hence making the selective epitaxial growth selectively while shifting the semiconductor substrate 34 by a stage 32. Thus, an apparatus for manufacturing a compound semiconductor is structured. In this way, an optical wave guide and semiconductor laser of an arbitrary configuration can be formed by the selective epitaxial growth.