A battery pack includes: cells, and electrode tabs including a positive electrode tab and a negative electrode tab which are connected with the power generation element, and which are provided to protrude from end portions of the outer member; frame members each including a front surface and a back surface on which the pair of the cells are mounted; conductive members each of which is disposed on the frame member, and each of which electrically connects the electrode tabs of the pair of the cells; and bus bars each of which electrically connects the conductive members disposed on the frame members of the plurality of the stacked frame members, and which are adjacent in a stacking direction.