A battery module comprising: a cell assembly comprising a plurality of secondary batteries that each comprise a plurality of electrode leads and are stacked in at least one direction; a module terminal comprising a connection terminal configured to provide electric connection with an external device; and a bus bar assembly comprising: a module bus bar comprising an upper plate portion and a lower plate portion that electrically connect the plurality of secondary batteries and the module terminal and each have at least one region separated from each other, a connection extending portion that extends to one side end portion of each of the upper plate portion and the lower plate portion to electrically connect the upper plate portion and the lower plate portion to each other, and a bent connecting portion that protrudes from a top of the upper plate portion by being bent in an outward direction and has one region combined to the module terminal; and a pressurizing bus bar pressurizing the plurality of electrode leads such that end portions of the plurality of electrode leads closely contact the lower plate portion, wherein the bus bar assembly further comprises a bus bar frame having an outer surface where the module bus bar is mounted and having a penetrating hole through which at least one of the plurality of electrode leads penetrates and protrudes, and wherein end portions of the plurality of electrode leads protrude in a front-and-back direction from the plurality of secondary batteries to penetrate through the penetrating hole of the bus bar frame, and the lower plate portion has a depressed structure recessed inward in a direction in which the plurality of electrode leads are contacted such as to accommodate and contact the end portions of the plurality of electrode leads. a cell assembly comprising a plurality of secondary batteries that each comprise a plurality of electrode leads and are stacked in at least one direction; a module terminal comprising a connection terminal configured to provide electric connection with an external device; and a bus bar assembly comprising: a module bus bar comprising an upper plate portion and a lower plate portion that electrically connect the plurality of secondary batteries and the module terminal and each have at least one region separated from each other, a connection extending portion that extends to one side end portion of each of the upper plate portion and the lower plate portion to electrically connect the upper plate portion and the lower plate portion to each other, and a bent connecting portion that protrudes from a top of the upper plate portion by being bent in an outward direction and has one region combined to the module terminal; and a pressurizing bus bar pressurizing the plurality of electrode leads such that end portions of the plurality of electrode leads closely contact the lower plate portion, wherein the bus bar assembly further comprises a bus bar frame having an outer surface where the module bus bar is mounted and having a penetrating hole through which at least one of the plurality of electrode leads penetrates and protrudes, and wherein end portions of the plurality of electrode leads protrude in a front-and-back direction from the plurality of secondary batteries to penetrate through the penetrating hole of the bus bar frame, and the lower plate portion has a depressed structure recessed inward in a direction in which the plurality of electrode leads are contacted such as to accommodate and contact the end portions of the plurality of electrode leads. a module bus bar comprising an upper plate portion and a lower plate portion that electrically connect the plurality of secondary batteries and the module terminal and each have at least one region separated from each other, a connection extending portion that extends to one side end portion of each of the upper plate portion and the lower plate portion to electrically connect the upper plate portion and the lower plate portion to each other, and a bent connecting portion that protrudes from a top of the upper plate portion by being bent in an outward direction and has one region combined to the module terminal; and a pressurizing bus bar pressurizing the plurality of electrode leads such that end portions of the plurality of electrode leads closely contact the lower plate portion, wherein the bus bar assembly further comprises a bus bar frame having an outer surface where the module bus bar is mounted and having a penetrating hole through which at least one of the plurality of electrode leads penetrates and protrudes, and wherein end portions of the plurality of electrode leads protrude in a front-and-back direction from the plurality of secondary batteries to penetrate through the penetrating hole of the bus bar frame, and the lower plate portion has a depressed structure recessed inward in a direction in which the plurality of electrode leads are contacted such as to accommodate and contact the end portions of the plurality of electrode leads.