A secondary battery is provided with first and second electrode assembly bodies and first and second negative electrode tab groups. The first and second negative electrode tab groups respectively have collected foil portions each constituted by a plurality of collected tab portions and extension portions. The extension portions of the respective tab groups have portions-to-be-welded and step portions. In the step portions, the plurality of tabs are laminated in a state that the end portions thereof are shifted in a step-like manner. The secondary battery is provided with an overlapped portion where the step portions of the first negative electrode tab group and the second negative electrode tab group are overlapped with each other in the lamination direction of the negative electrode tabs.