The present invention provides a gas-phase growth apparatus in which an upper part of a circular susceptor 13 on the upper surface of which a substrate 17 is arranged is provided into a circular opening 12a formed at a bottom wall of the flow channel 12, while rotating the susceptor, the substrate is heated by a heater 14 provided under the susceptor through the susceptor, a reaction gas is supplied into the flow channel, and a thin film is produced on the substrate, wherein a rotation driving device 18 for rotating the susceptor is arranged in a state of surrounding the heater, and includes a cylindrical rotation member 19 for supporting the circumferential edge of the susceptor by the top end.