A chemical vapor deposition apparatus comprises a starting material container holding a starting material in a liquid state, a starting gas generating container into which the liquid starting material is fed from the starting material container, a means for keeping constant the liquid level of the liquid starting material held in the starting gas generating container, a means for injecting a bubbling gas from the outside into the liquid starting material held in the starting gas generating container, thereby bubbling the starting gas, and a reaction chamber into which a mixed gas of the starting gas and the bubbling gas are fed.