A battery pack includes a battery group including battery rows consecutively disposed adjacent to each other, with the battery rows including secondary batteries disposed parallel to each other and spaced apart from each other, a frame for surrounding the battery group, and a plurality of first ribs that are each disposed between adjacent battery rows. The first ribs include supporting grooves that are formed in lateral surfaces of the first ribs and accommodate portions of edges of the secondary batteries, and ends of each of the first ribs are coupled to the frame.