A chemical vapor deposition apparatus includes: a reaction chamber, a reaction area in the upper portion of the reaction chamber, an exhaust area in the bottom portion of the reaction chamber and a pumping apparatus connected to the outside of the reaction chamber. The exhaust area includes an isolating device dividing the exhaust area into an exhaust chamber and a storage chamber. The isolating device has a sidewall with gas openings connecting the exhaust chamber and the storage chamber. The exhaust area further includes a scraping component that can move up and down between the upper end and the lower end of the gas openings.