A battery frame of the present invention has; any one of a conductive member and an insulating member which are sandwiched between electrode tabs of flat cells arranged in a stacking direction when a battery is formed, the conductive member electrically connecting the flat cells to each other and the insulating member electrically insulating the flat cells from each other; a holding member which holds any one of the conductive member and the insulating member so that the conductive member or the insulating member can swing in the stacking direction; and an electrode supporting portion in which the holding member is provided and which supports each of the electrode tabs of the flat cells. By this structure, it is possible to prevent deformation of the battery frame during the formation of the battery.