A battery module comprising: a first cooling plate configured for supporting a first group of battery packs and in which a first cooling tube is embedded; a second cooling plate configured for supporting a second group of battery packs and in which a second cooling tube is embedded; and a third cooling plate configured for supporting a third group of battery packs and in which a third cooling tube is embedded, wherein the second cooling plate is placed at a second level higher than a first level of the first cooling plate forming a bottom of the battery module, wherein legs L are provided on the second cooling plate to support the second cooling plate above the first cooling plate with a first pack accommodation region therebetween; and wherein the first cooling plate as a whole has a T-shape with a length part extending in a first direction and a width part extending in a second direction perpendicular to the first direction, wherein the second cooling plate is positioned above and extends in parallel with the length part of the first cooling plate, wherein the third cooling plate is positioned above and extends in parallel with the width part of the first cooling plate, wherein legs L are provided on the third cooling plate to support the third cooling plate above the first cooling plate with a second pack accommodation region therebetween, wherein each of the first to third cooling tubes (C1, C2, C3) includes a plurality of tubes configured for transporting a cooling medium, wherein the plurality of tubes of the first cooling tube comprises a passage passing through a rear branch part and connected to the third cooling tube and a bypass passage bypassing the rear branch part and having a diameter smaller than a diameter of the passage connected to the third cooling tube. a first cooling plate configured for supporting a first group of battery packs and in which a first cooling tube is embedded; a second cooling plate configured for supporting a second group of battery packs and in which a second cooling tube is embedded; and a third cooling plate configured for supporting a third group of battery packs and in which a third cooling tube is embedded, wherein the second cooling plate is placed at a second level higher than a first level of the first cooling plate forming a bottom of the battery module, wherein legs L are provided on the second cooling plate to support the second cooling plate above the first cooling plate with a first pack accommodation region therebetween; and wherein the first cooling plate as a whole has a T-shape with a length part extending in a first direction and a width part extending in a second direction perpendicular to the first direction, wherein the second cooling plate is positioned above and extends in parallel with the length part of the first cooling plate, wherein the third cooling plate is positioned above and extends in parallel with the width part of the first cooling plate, wherein legs L are provided on the third cooling plate to support the third cooling plate above the first cooling plate with a second pack accommodation region therebetween, wherein each of the first to third cooling tubes (C1, C2, C3) includes a plurality of tubes configured for transporting a cooling medium, wherein the plurality of tubes of the first cooling tube comprises a passage passing through a rear branch part and connected to the third cooling tube and a bypass passage bypassing the rear branch part and having a diameter smaller than a diameter of the passage connected to the third cooling tube.