A battery module, comprising: a plurality of battery cells aligned in one direction, each battery cell of the plurality of battery cells including a terminal portion on a first surface of a respective battery cell; a bus-bar electrically connect between the terminal portions of the plurality of battery cells; and a bus-bar holder positioned on the first surfaces of the plurality of battery cells, the bus-bar holder including support portions (131, 132) configured to support two different surfaces of the bus-bar, respectively, wherein two different surfaces of the bus-bar include a first surface facing the first surfaces of the battery cells, and a second surface opposite to the first surface of the bus-bar, wherein the support portions (131, 132) of the bus-bar holder include: a first support portion configured to support the first surface of the bus-bar; and a second support portion configured to support the second surface of the bus-bar, wherein the second support portion of the bus-bar holder includes a pair of second support portions configured to respectively support two sides of the bus-bar, the first support portion being between the pair of second support portions, wherein the bus-bar includes: a first connecting portion connected to the terminal portion of a first battery cell among the plurality of battery cells; a second connecting portion connected to the terminal portion of a second battery cell adjacent to the first battery cell; and a bending portion connecting the first and second connecting portions (123, 124), the bending portion protruding away from the first and second battery cells, wherein the first support portion is positioned between the bending portion and the corresponding battery cells, the second support portion being positioned on the second surface of the first and second connecting portions (123, 124), wherein the first support portion protrudes away from the corresponding battery cells, the first support portion corresponding to a shape of the bending portion, characterized in that the bus-bar holder is made of insulating material and the bus-bar is connected to the terminal portion through welding wherein the bus-bar further comprises an extending portion, the extending portion extending from at least one of the first and second connecting portions (123, 124) to a top surface of the bus-bar holder wherein the extending portion has a bus-bar fastening portion at an end portion thereof, the bus-bar fastening portion extending on a holder fastening portion of the bus-bar holder wherein a hole is formed in the bus-bar fastening portion and the holder fastening portion. a plurality of battery cells aligned in one direction, each battery cell of the plurality of battery cells including a terminal portion on a first surface of a respective battery cell; a bus-bar electrically connect between the terminal portions of the plurality of battery cells; and a bus-bar holder positioned on the first surfaces of the plurality of battery cells, the bus-bar holder including support portions (131, 132) configured to support two different surfaces of the bus-bar, respectively, a first support portion configured to support the first surface of the bus-bar; and a second support portion configured to support the second surface of the bus-bar, wherein the second support portion of the bus-bar holder includes a pair of second support portions configured to respectively support two sides of the bus-bar, the first support portion being between the pair of second support portions, a first connecting portion connected to the terminal portion of a first battery cell among the plurality of battery cells; a second connecting portion connected to the terminal portion of a second battery cell adjacent to the first battery cell; and a bending portion connecting the first and second connecting portions (123, 124), the bending portion protruding away from the first and second battery cells, wherein the first support portion is positioned between the bending portion and the corresponding battery cells, the second support portion being positioned on the second surface of the first and second connecting portions (123, 124), wherein the first support portion protrudes away from the corresponding battery cells, the first support portion corresponding to a shape of the bending portion, characterized in that the bus-bar holder is made of insulating material and the bus-bar is connected to the terminal portion through welding wherein the bus-bar further comprises an extending portion, the extending portion extending from at least one of the first and second connecting portions (123, 124) to a top surface of the bus-bar holder wherein the extending portion has a bus-bar fastening portion at an end portion thereof, the bus-bar fastening portion extending on a holder fastening portion of the bus-bar holder wherein a hole is formed in the bus-bar fastening portion and the holder fastening portion.