A chemical vapor deposition apparatus is provided, which includes: a chamber having an inner space; a gas feed member for supplying a gas into the chamber; a susceptor disposed in the chamber and supporting a substrate; a diffuser partitioning the inner space of the chamber into first and second partitions and having a plurality of holes connecting the first partition and the second partition for gas communication; a diffuser frame incorporated into the diffuser; and an insulating frame disposed between the chamber and the diffuser.