Abstract: The present invention is to provide a resin film having both water impermeability and moisture permeability. The polyolefin stretched porous film according to an embodiment of the present invention contains a polyolefin-based resin and a fine filler having an average primary particle size of 0.05 to 0.8 ?m, and has a communicating void. Furthermore, the polyolefin stretched porous film according to an embodiment of the present invention contains a hydrophobizing agent, a water permeability measured in accordance with JIS Z 0221 is from 10000 to 85000 seconds, and a moisture permeability measured in accordance with JIS Z 0208 is from 300 to 2500 g/m2·24 h.

Abstract: A solar-cell back sheet comprising a laminate of an adhesive layer (2) containing 50 to 100% by weight of a thermoplastic resin and 0 to 50% by weight of an inorganic filler or an organic filler, and a base layer (1) containing 30 to 95% by weight of a polypropylene resin, and 5 to 70% by weight of an inorganic filler or an organic filler, and being stretched in at least one direction with a porosity of 55% or less, in which a reflectance for light of 750 nm wavelength is 90% or more and a partial discharge voltage per micrometer is 7.5 V or more, is excellent in partial discharge voltage, and can be reduced in thickness, and has excellent adhesion for a sealing material.