A non-aqueous electrolytic secondary battery that can prevent a drop in the power even in a large current discharge is provided. Porosity of a separator is larger than or the same as porosity of a positive electrode mixture and a porosity of a negative electrode mixture. Particularly, the porosity of the positive electrode mixture is 20% to 50%, the porosity of the negative electrode mixture is 20% to 50%, and the porosity of the separator is 20% to 60%. The separator becomes rich in the volume of the electrolytic solution that infiltrates into interfacial aperture between the separator and the negative electrode. When the large current discharge is carried out in a short time, lithium-ions are released/occluded from the electrodes and the electrolytic solution can gain the released/occluded lithium-ions with a small interfacial resistance.