A battery module comprising: a case providing an internal space; a plurality of battery cells disposed in the internal space of the case; and at least one cooling unit interposed between the battery cells to be in surface contact with the battery cells and dissipating heat generated by the battery cells externally, wherein the at least one cooling unit comprises: a cooling frame formed as a hollow quadrangular frame, a cooling plate disposed inside the cooling frame, and disposed in such a manner that two surfaces of the cooling plate are in surface contact with the battery cells; and a heat dissipating member connected to the cooling plate and disposed outside of the case; wherein the case comprises a main frame having two open sides and side covers coupled to the two open sides of the main frame to form the internal space, wherein the main frame comprises two buffer plates disposed in a central portion of the main frame, and the two buffer plates are spaced apart from each other by a predetermined distance and the two buffer plates comprise protrusions protruding in a single direction, disposed in such a manner that the protrusions contact each other, wherein the main frame is coupled to the side covers in such a manner that protrusions formed on the main frame are inserted in grooves formed in the side covers, wherein the side covers are bonded to the main frame by irradiating a laser beam onto the protrusions. a case providing an internal space; a plurality of battery cells disposed in the internal space of the case; and at least one cooling unit interposed between the battery cells to be in surface contact with the battery cells and dissipating heat generated by the battery cells externally, wherein the at least one cooling unit comprises: a cooling frame formed as a hollow quadrangular frame, a cooling plate disposed inside the cooling frame, and disposed in such a manner that two surfaces of the cooling plate are in surface contact with the battery cells; and a heat dissipating member connected to the cooling plate and disposed outside of the case; wherein the case comprises a main frame having two open sides and side covers coupled to the two open sides of the main frame to form the internal space, wherein the main frame comprises two buffer plates disposed in a central portion of the main frame, and the two buffer plates are spaced apart from each other by a predetermined distance and the two buffer plates comprise protrusions protruding in a single direction, disposed in such a manner that the protrusions contact each other, wherein the main frame is coupled to the side covers in such a manner that protrusions formed on the main frame are inserted in grooves formed in the side covers, wherein the side covers are bonded to the main frame by irradiating a laser beam onto the protrusions. a cooling frame formed as a hollow quadrangular frame, a cooling plate disposed inside the cooling frame, and disposed in such a manner that two surfaces of the cooling plate are in surface contact with the battery cells; and a heat dissipating member connected to the cooling plate and disposed outside of the case; wherein the case comprises a main frame having two open sides and side covers coupled to the two open sides of the main frame to form the internal space, wherein the main frame comprises two buffer plates disposed in a central portion of the main frame, and the two buffer plates are spaced apart from each other by a predetermined distance and the two buffer plates comprise protrusions protruding in a single direction, disposed in such a manner that the protrusions contact each other, wherein the main frame is coupled to the side covers in such a manner that protrusions formed on the main frame are inserted in grooves formed in the side covers, wherein the side covers are bonded to the main frame by irradiating a laser beam onto the protrusions.