A non-aqueous electrolyte secondary battery having a high negative electrode energy density, good safety and high discharge characteristics is provided without damaging manufacturing facilities. The non-aqueous electrolyte secondary battery includes a positive electrode, a negative electrode, a porous heat-resistant layer interposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte. The negative electrode comprises a negative electrode current collector and a negative electrode mixture layer on a surface of the negative electrode current collector, and the negative electrode mixture layer has an active material density of 1.5 g/ml to 1.8 g/ml. The porous heat-resistant layer is carried on the negative electrode, and the porous heat-resistant layer comprises magnesium oxide particles having a mean particle size of 0.5 μm to 2 μm.