The present invention aims to provide a continuous forming method and apparatus for functional deposited films having excellent characteristics while preventing any mutual mixture of gases between film forming chambers having different pressures, wherein each of semiconductor layers of desired conduction type is deposited on a strip-like substrate within a plurality of film forming chambers, by plasma CVD, while the strip-like substrate is being moved continuously in a longitudinal direction thereof through the plurality of film forming chambers connected via a gas gate having the structure of introducing a scavenging gas into a slit-like separation passage, characterized in that at least one of the gas gates connecting the i-type layer film forming chamber for forming the semiconductor junction and the n- or p-type layer film forming chamber having higher pressure than the i-type layer film forming chamber has the scavenging gas introducing position disposed on the n- or p-type layer film forming chamber side off the center of the separation chamber of the gas gate.