Non-aqueous electrolyte storage element including; positive electrode including positive electrode material layer, which contains positive electrode active material capable of reversibly accumulating and releasing anions; negative electrode including negative electrode material layer, which contains negative electrode active material capable of reversibly accumulating and releasing cations; separator disposed between the positive electrode and the negative electrode; and non-aqueous electrolyte containing electrolyte salt, the non-aqueous electrolyte storage element satisfying formulae: 0.5≤[(V1+V2+V3)/V4]≤0.61; and 0.14≤P1/P2≤0.84, where V1 is volume of pores of the positive electrode material layer per unit area of the positive electrode, V2 is volume of pores of the negative electrode material layer per unit area of the negative electrode, V3 is volume of pores per unit area of the separator, and V4 is total volume of the non-aqueous electrolyte storage element, and P1 is porosity of the positive electrode material layer, and P2 is porosity of the separator.