It is a task of the invention to provide a battery that allows a gas produced inside a flat wound electrode body to be easily discharged to the outside of the electrode body, and restrains an electrolytic solution (a retained electrolytic solution) extruded from the flat wound electrode body through charge/discharge from directly flowing out to the outside of the flat wound electrode body, and a method of manufacturing this battery. The battery is equipped with a flat wound electrode body, a collector member, and a retained electrolytic solution. The flat wound electrode body has an active material layer wound portion that is obtained by winding an electrode plate, has a flat oval cross-section, and has a wound active material layer forming portion, and an exposed wound portion that has a wound foil exposed portion. An exposed wound central portion is detached from at least one of two exposed wound end portions while maintaining contact with an active material layer wound portion that is adjacent to the exposed wound central portion in an axial direction. The collector member is joined to the exposed wound central portion.