A battery module comprising: a battery cell stack constituted by a plurality of battery cells, the battery cell stack being configured such that the battery cells are stacked in a state in which the battery cells are adjacent to each other laterally; a first module cover and a second module cover coupled to each other while covering electrode terminals provided on opposite sides of the battery cell stack; and terminal plates for electrically connecting electrode terminals of the battery cells to each other; wherein - the battery cell stack is provided in one end thereof with a step part; - a battery management system (BMS, 140) is mounted in the step part of the battery cell stack for controlling an operation of the battery module; and - the battery module comprises voltage sensing wires arranged on the battery cell stack, each of the voltage sensing wires having one end connected to a corresponding one of voltage sensing terminals formed on portions of the terminal plates the other end connected to the BMS, - ribs (161, 162) for fixing the voltage sensing wires are alternately formed on upper ends of the first module cover and the second module cover, wherein the ribs (161, 162) comprise: first ribs formed to have a bar shape that protrudes in a direction in which the module covers (121, 122) are coupled to each other for fixing the voltage sensing wires in spaces defined between the battery cells, wherein the first ribs protrude from inside ends of the module covers (121, 122) in the direction in which the module covers (121, 122) are coupled to each other, and the first ribs push the voltage sensing wires into the spaces defined between the battery cells and couple the voltage sensing wires into openings formed in the module covers (121, 122), second ribs having a groove that is concavely formed in protrusions protruding from the upper end surfaces of the module covers (121, 122) such that the groove of each of the second ribs corresponds to the outer diameter of the voltage sensing wires and that the voltage sensing wires are fitted into the second ribs from above. a battery cell stack constituted by a plurality of battery cells, the battery cell stack being configured such that the battery cells are stacked in a state in which the battery cells are adjacent to each other laterally; a first module cover and a second module cover coupled to each other while covering electrode terminals provided on opposite sides of the battery cell stack; and terminal plates for electrically connecting electrode terminals of the battery cells to each other; - the battery cell stack is provided in one end thereof with a step part; - a battery management system (BMS, 140) is mounted in the step part of the battery cell stack for controlling an operation of the battery module; and - the battery module comprises voltage sensing wires arranged on the battery cell stack, each of the voltage sensing wires having one end connected to a corresponding one of voltage sensing terminals formed on portions of the terminal plates the other end connected to the BMS, - ribs (161, 162) for fixing the voltage sensing wires are alternately formed on upper ends of the first module cover and the second module cover, first ribs formed to have a bar shape that protrudes in a direction in which the module covers (121, 122) are coupled to each other for fixing the voltage sensing wires in spaces defined between the battery cells, wherein the first ribs protrude from inside ends of the module covers (121, 122) in the direction in which the module covers (121, 122) are coupled to each other, and the first ribs push the voltage sensing wires into the spaces defined between the battery cells and couple the voltage sensing wires into openings formed in the module covers (121, 122), second ribs having a groove that is concavely formed in protrusions protruding from the upper end surfaces of the module covers (121, 122) such that the groove of each of the second ribs corresponds to the outer diameter of the voltage sensing wires and that the voltage sensing wires are fitted into the second ribs from above.