Abstract: A bus bar for secondary battery is provided to electrically connect a plurality of secondary batteries in high reliability. The bus bar includes a plate section which is electrically conductive, opening sections which are provided for said plate section and in which convex electrode terminals of secondary batteries are inserted, respectively; and first slit sections formed to extend ends of the plate section from said opening sections, respectively. A diameter of said opening section is smaller than a diameter of said electrode terminal such that the inserted electrode terminal is fastened.