Abstract: Disclosed is an apparatus for chemical vapor deposition including: a dome-shaped upper chamber having a half-round surface or a curved surface of a predetermined angle; a shower head disposed in the upper chamber, for ejecting a reaction gas for film deposition straight or radially according to the shape of the upper chamber; a lower chamber sealed off from the upper chamber by way of an O-ring; a heater disposed at the center of the bottom surface of the lower chamber as a heat energy source for forming the films; and a nozzle for ejecting the reaction gas and preventing entrance of the reaction gas from the bottom of the heater. The apparatus ejects the reaction gas for film deposition straight or radially onto the surface of the wafer to secure films excellent in deposition uniformity and remarkably reduce the formation of products in the chamber.