A nonaqueous electrolyte secondary battery provided by the present invention includes an electrode body in which a positive electrode sheet and a negative electrode sheet 20 are laminated with a separator sheet 40 interposed therebetween. A porous layer 42 including an inorganic filler and a binder is formed on at least one surface of the separator sheet 40. The surface of the porous layer 42 is made uneven by forming peaks and valleys, and a maximum difference of elevation on an uneven surface 42a is 0.2 μm to 1.7 μm.