Porous film, battery separator comprising the film, and non-aqueous electrolyte battery using the separator

A porous film having excellent permeability and mechanical strength and having resistance to film breakage at high temperatures, a battery separator comprising the porous film, and a non-aqueous electrolyte battery using the separator. The porous film comprises a crosslinked material which comprises a polyolefin resin and an ethylene-propylene-diene terpolymer crosslinked therewith.