A continuous plasma CVD apparatus, characterized in that frequency of high-frequency bias is in the range of 50-900 KHz, a blocking condenser is provided between a thin film and a high-frequency source so that the product C·f of electrostatic capacity C of the blocking condenser and frequency f of the high-frequency source is 0.02 [F·Hz] or more, and the total of impedances of all the rollers provided in the route of from a substrate unwind roller to a rotating drum is 10 k&OHgr; or more and the total of impedances of all the rollers provided in the route of from the rotating drum to a wind roller is 10 k&OHgr; or more. According to this apparatus, it becomes possible to continuously form a film without causing damage and deterioration of the substrate.