In a plasma CVD apparatus, unnecessary discharge such as arc discharge is prevented, the amount of particles due to peeling of films attached to a reaction chamber is reduced, and the percentage of a time contributing to production in hours of operation of the apparatus is increased while enlargement of the apparatus and easy workability are maintained. The plasma CVD apparatus is configured such that in a conductive reaction chamber 104 with a power source 113, a vacuum exhausting means 118, and a reaction gas introduction pipe 114, plasma 115 is generated in a space surrounded by an electrode 111, a substrate holder 112, and an insulator 120.