TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Agent: The coloring agent which consists of inorganic compound is a white coloring agent.Preferred Composition: The filler layer contains silicon in an amount of 8-3,500 ppm as a polymerization silicon amount. A silanol condensed catalyst is not contained in the filler layer.Preferred Property: The reflectance filler layer for solar cell modules in 400-1,200 nm wavelength range is 40% or more.    TECHNOLOGY FOCUS - POLYMERS - Preferred Layer: The filler layer has further polyethylene as additional component. The polyethylene for polymerization and polyethylene as additional component is at least 1 polyethylene selected from low density polyethylene, medium density polyethylene, high density polyethylene, very low density polyethylene, ultra low density polyethylene and linear low density polyethylene. The amount of silane-modified resin contained in the filler layer is 1-80 wt.%. EXAMPLE - Silane modified resin was prepared using linear low density polyethylene having density of 0.898 g/cm3 and melt flow rate of 2 g/10 minutes, vinyl trimethoxy silane and dicumyl peroxide. Linear low density polyethylene (95) (in wt.pts) having density of 0.898 g/cm3, antioxidant and weather proof master batch (comprising linear low density polyethylene (85), phosphorus type thermostabilizer (5), benzophenone type ultraviolet absorber (7.5), hindered amine type optical stabilizer (2.5)) (5) and white master batch TET1KA861 (10) containing 70 wt.% titanium dioxide were mixed to the obtained silane-modified resin (5). The resulting mixture was supplied to a extruder and film molding was performed at extrusion temperature of 230degreesC. A sheet with thickness of 600 microns was obtained as filler layer. The filler layer was used for rear side and solar cell module was obtained, and filler layer for surface side was formed using same composition without adding white master batch. The filler layer had gel fraction of 0% and peeling strength of reverse side protection sheet. The cell module had conversion efficiency relative value of 1.08.