<p>A plasma CVD apparatus in which microwave power is supplied into a reaction chamber (2) provided inside an annular waveguide (5) through an antenna (20) provided the inner peripheral part of the waveguide (5) so as to produce a plasma inside the reaction chamber (2) and to form a film by a vapor growth synthesizing method. A cooler (27) is disposed between the annular waveguide (5) and the reaction chamber (2) so as to maintain the low temperature of the annular waveguide (5). <IMAGE></p>
