A non-aqueous electrolyte secondary battery comprising: an electrode plate assembly; a non-aqueous electrolyte; and an outer jacket accommodating the electrode plate assembly and the non-aqueous electrolyte therein, the electrode plate assembly comprising a positive electrode plate, a negative electrode plate and a separator interposed between the positive electrode plate and the negative electrode plate, the separator comprising a polyolefin resin, wherein (1) the separator comprises at least one layer comprising a polypropylene resin, (2) the layer comprising a polypropylene resin contains an antioxidant with a melting point of 60.degree. C. or higher, and (3) the layer comprising a polypropylene resin and the positive electrode are in contact with one another.