NOVELTY - A plasma chemical vapor deposition (CVD) apparatus comprises vacuum vessel which is provided with exhaust system, pair of electrodes provided with first electrode (2) of electrically unearthed parallel plate and second electrode of parallel plate which mounts substrate with gas emission hole for ejecting source gas and diluent gas, high frequency electric power supply system which supplies high frequency electric power to electrode of pair, and recessed parts or holes which are formed in opposing surface facing second electrode of first electrode.    USE - Plasma chemical vapor deposition apparatus for manufacturing silicon system film (claimed) used for electric power generation film of thin film solar cell, silicon film solar battery, passivation film and reflecting film of polycrystalline silicon solar cell, and formation of insulating films e.g. thin-film transistor, silicon nitride film and silicon oxide film for LCD.    ADVANTAGE - The apparatus has high speed, improves productivity and reduces cost.    DETAILED DESCRIPTION - A plasma chemical vapor deposition (CVD) apparatus comprises vacuum vessel which is provided with exhaust system, supply source of source gas, supply source of diluent gas which dilutes source gas, gas introduction tube which introduces source gas and diluent gas into vacuum vessel, pair of electrodes provided with first electrode (2) of electrically unearthed parallel plate and second electrode of parallel plate which mount substrate with gas emission hole for ejecting source gas and diluent gas, high frequency electric power supply system which supplies high frequency electric power to electrode of pair, thin film which is formed in substrate installed in vacuum vessel, recessed parts or holes which are formed in opposing surface facing second electrode of first electrode, source gas ejection port installed in bottom face of recessed parts or holes which ejects source gas or mixed gas of source gas and diluent gas, and diluent gas ejection port (5a) installed in flat part except part of recessed parts or holes of opposing surface which ejects diluent gas. An INDEPENDENT CLAIM is included for a manufacturing method of silicon system film.    DESCRIPTION OF DRAWING(S) - The drawing shows a sectional view of the first electrode used for plasma chemical vapor deposition apparatus.    First electrode (2)    Diluent gas ejection port (5a)    Jet stream of diluent gas (17)    Jet stream of source gas (18)    Mixing zone (19)