Disclosed is a battery module with improved energy density and cooling efficiency. To achieve the object, the battery module according to the present disclosure includes a plurality of cylindrical battery cells electrically connected to each other and arranged in a horizontal direction, an upper frame mounted on the plurality of cylindrical battery cells, and a lower frame mounted below the plurality of cylindrical battery cells, wherein a pressing portion is formed in any one of the upper frame and the lower frame to elastically press the plurality of cylindrical battery cells in a horizontal inward direction for a dense arrangement of the plurality of cylindrical battery cells.