NOVELTY - Several photoelectric conversion elements are formed on flexible metal substrate (10). An organic insulating protection film (3) is provided covering conversion elements, such that light transparency for each element is secured. An inorganic insulating protection film (60) is formed on transparent electrode layer (50) of conversion element, such that light transparency on light receiving side of conversion element is secured. The layer structure with silicon oxynitride layer as outermost layer of structure is provided in inorganic insulation protection film.    USE - Flexible solar cell module e.g. integrated type solar cell module and cell-string connected type solar cell module.    ADVANTAGE - The photoelectric conversion efficiency, weather resistance property and water vapor barrier properties of the flexible solar cell module are improved, by optically matching the refractive induces of films formed on outer side of transparent electrode layer. The cost of the flexible solar cell module is reduced efficiently, by avoiding usage of the expensive water vapor barrier film.    DETAILED DESCRIPTION - The refractive index of silicon oxynitride layer is set about 1.5-1.9. A silicon nitride layer is provided in the layer structure. The silicon oxynitride layer and silicon nitride layer are provided one above the other from the side of photoelectric conversion element, resulting in formation of two-layered structure. The refractive index of silicon oxynitride layer is continuously increased from outer side towards photoelectric conversion element side. The refractive index of organic insulating protection film is set to 1.35-1.50. The refractive index of transparent electrode layer is set about 1.9-2.00.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic cross-sectional view of the flexible solar cell module.    Flexible solar cell module (1)    Organic insulating protection film (3)    Flexible metal substrate (10)    Photoelectric conversion layer (30)    Transparent electrode layer (50)    Inorganic insulating protection film (60)