The present invention provides a non-aqueous electrolyte secondary battery with various improved battery characteristics and a method for manufacturing such a non-aqueous electrolyte secondary battery. In the present invention, the battery manufacturing method includes accommodating and sealing a flat battery element (4) in which a positive electrode plate (41) and a negative electrode plate (42) stacked together via a separator (43), together with a non-aqueous electrolyte including a surplus electrolyte and at least one kind of electrolyte additive, in a laminate film exterior member (5), and then, subjecting the thus-assembled battery (1) to charging operation including at least initial charging in a state where a pressure is applied to a flat surface of the battery element from the outside of the exterior member (5).