Plasma CVD apparatus, method of manufacturing a semiconductor layer, A method of manufacturing a thin film solar cell and method of cleaning a plasma CVD apparatus

A plasma CVD apparatus comprising: a film forming chamber 4; a holding part that holds a substrate to be processed which is disposed in the film forming chamber 4; a jet head 5, which faces the holding member disposed in the film forming chamber 4, supplying raw material gas and a plasma is generated from the raw material gas; a free radical generating chamber 8 which is disposed on an opposite side of the jet head 5 with respect to the holding part and generates radicals from the process gas; and a closure element 9 which can be opened and closed and is provided between the ejection head 5 and the radical generating chamber. 8