An object of this present invention is to provide: a lithium-ion secondary battery 1 constructed to easily interpose an electrical insulating protection film 41 between a battery container 2 and an electricity-generating element 3, to facilitate automatic mounting of the insulating protection film 41, and thus to be highly producible; and a method of manufacturing the battery. The lithium-ion secondary battery 1 of the invention is characterized in that the battery is electrically insulated between the battery container 2 and the electricity-generating element 3, and in that the insulating protection film 41 of a sheet-like form is wrapped around the electricity-generating element 3.