A battery module having a plurality of battery cells electrically connected to each other is disclosed. The battery module includes a plurality of cartridges, each of which includes a frame member, to opposite sides of which battery cells are mounted, each of the cartridges being provided at corners thereof with fastening parts, through which adjacent cartridges are coupled to each other in order to constitute a cartridge assembly, a pair of end plates mounted to opposite side surfaces of the cartridge assembly so as to cover outermost cartridges, and a busbar assembly mounted to one surface of the cartridge assembly, the busbar assembly including busbars for electrical connection between electrode terminals of the battery cells, wherein each of the cartridges is configured such that a cooling fin, with opposite surfaces of which the battery cells are in contact for thermal conduction, is mounted to the middle part of the cartridge, when viewed in vertical section, one end of the cooling fin being exposed outward from the cartridge, and gripping parts for mounting the battery cells in position are formed on the inner surface of the frame member of the cartridge.