A single-wafer-processing type CVD apparatus includes: (a) a reaction chamber including: (i) a susceptor having at least one gas discharge hole to flow a gas into the reaction chamber via a back side and a periphery of the wafer into the reaction chamber; (ii) a showerhead; (iii) an exhaust duct positioned in the vicinity of the showerhead and provided circularly along an inner wall of the reaction chamber; and (iv) a circular separation plate provided coaxially with the exhaust duct to form a clearance with the bottom of the exhaust duct; and (b) a temperature-controlling apparatus for regulating the temperature of the showerhead. The separation plate has a sealing portion to seal a periphery of the susceptor and to separate the reaction chamber from a wafer-handling chamber when the susceptor rises.