To provide a vapor phase growth apparatus of horizontal system in which generation and adhesion of by-products are prevented by dissipating radiation heat from a susceptor efficiently, and a high quality crystal layer can be grown even if crystal growth is carried out repeatedly.

A material gas supply section defining a material gas passage is disposed on the upstream side of the material gas passage for a substrate holding section, and has a material gas supply guide composed of a material transmitting infrared rays radiated from the substrate holding section. The material gas supply guide has an infrared ray exit part consisting of an uneven structure formed on a surface different from a surface defining the material gas passage.