The invention relates to a battery module and a manufacturing method thereof. The battery group including a plurality of battery cells stacked with each other; a cooling plate which is located in contact with one side of the battery group to cool the plurality of battery cells; and a case which is located on the other side of the battery group so as to surround the battery group, wherein the casecomprises an upper cover located on the other side of the battery group; and side covers which vertically extend from the upper cover so as to surround side portions of the plurality of battery cellsfrom which electrode tabs protrude.