A battery module includes a pair of side plates arranged along two wall faces, opposing to each other in a stacking direction of battery cells, of wall faces of the battery module, a lower plate that swingably supports one end of the pair of side plates by a hinge mechanism and that is arranged along one wall face of the battery module, and an upper plate that is arranged along the wall face of the battery module so as to be opposite to the lower plate, and that connects the other ends of the pair of side plates, wherein the side plates and the upper plate are tightened and fixed by use of a fastening member with pressure being applied in the stacking direction of the battery cells in order to fix the battery module.