Battery pack

There is provided a battery pack in which a pair of ribs (22) are formed at an inner frame (20) to extend toward plane portions (10e, 10f) of a bare cell (10), so that the inner frame (20) can be fixed at the exact position of the bare cell (10). In one embodiment, a battery pack includes a bare cell (10) having a pair of first side portions (10a, 10b) opposite to each other, a pair of second side portions (10c, 10d) opposite to each other, and a pair of plane portions (10e, 10f) opposite to each other. The second side portions (10c, 10d) and the plane portions (10e, 10f) are connected to ends of the first side portions (10a, 10b). A protection circuit module (30) is electrically connected to the bare cell (10). An inner frame (20) is provided between the bare cell (10) and the protection circuit module (30). The inner frame (20) has at least a pair of ribs (22) opposite to each other while extending toward the plane portions (10e, 10f) of the bare cell (10).