Non-Aqueous Electrolyte Secondary Battery

To provide a non-aqueous electrolyte secondary battery exhibiting improved battery durability in a flat stacked type battery having a high capacity, a high density and a large area. A solution is a flat stacked type non-aqueous electrolyte secondary battery including a power generating element including: a positive electrode comprising a positive electrode active material layer containing a positive electrode active material formed on a surface of a positive electrode current collector, a negative electrode comprising a negative electrode active material layer containing a negative electrode active material formed on a surface of a negative electrode current collector, and an electrolyte layer, wherein a ratio of a rated capacity to a pore volume of the negative electrode active material layer is 1.12 Ah/cc or more, a ratio of a battery area to a rated capacity is 4.0 cm/Ah or more, and a rated capacity is 30 Ah or more, and the electrolyte layer contains an electrolyte solution containing an electrolyte salt dissolved and a value obtained by dividing a weight of an electrolyte salt in pores in the negative electrode active material layer by a weight of the negative electrode active material is 0.031 or more.