A battery module comprising: a battery stack configured to comprise a plurality of batteries stacked, each of the plurality of batteries being rectangular in shape and including a valve portion and at least one output terminal (16 16a 16b), the valve portion being configured to release a gas generated in the batteries, into an exhaust duct arranged in the stacking direction of the plurality of batteries and configured to be connected to the valve portion of each of the plurality of batteries, and the at least one output terminal (16 16a 16b) comprising one of a positive or a negative output terminal; a plurality of bus bars (28 28a 28b 28c 28d) configured to electrically connect the output terminals (16 16a 16b) of each of the plurality of batteries together, the plurality of bus bars (28 28a 28b 28c 28d) grouping the plurality of batteries into a plurality of battery units (42a 42b 42c 42d) each including at least two of the plurality of batteries, the plurality of bus bars (28 28a 28b 28c 28d) each configured to connect in parallel the output terminals (16 16a 16b) of the at least two of the plurality of batteries in a corresponding one of the battery units (42a 42b 42c 42d), and the plurality of bus bars (28 28a 28b 28c 28d) further configured to connect, in series, the plurality of battery units (42a 42b 42c 42d); characterized in that, the exhaust duct comprises at least one through-hole that connects inside and outside of the exhaust duct on a first wall surface facing a first bus bar on a respective at least one a gas distribution path, said at least one gas distribution path being formed from the valve portion to the first busbar through the through-hole of the exhaust duct, the at least one through-hole being arranged in a first direction, said first direction being perpendicular to the stacking direction, and in which the valve portion and the at least one output terminal (16 16a 16b) are arranged and, the battery module further comprises: a metal filter disposed on the at least one gas distribution path and, the metal filter is comprised in a first plurality of metal filters corresponding to a first plurality of gas distribution paths, disposed in the stacking direction of the plurality of batteries, over a range corresponding to batteries belonging to a first terminal group of a first battery unit (42a 42b 42c 42d), to which a first bus bar of the plurality of bus bars (28 28a 28b 28c 28d) is fixed, and each metal filter of the first plurality of metal filters is disposed on a corresponding gas distribution path. a battery stack configured to comprise a plurality of batteries stacked, each of the plurality of batteries being rectangular in shape and including a valve portion and at least one output terminal (16 16a 16b), the valve portion being configured to release a gas generated in the batteries, into an exhaust duct arranged in the stacking direction of the plurality of batteries and configured to be connected to the valve portion of each of the plurality of batteries, and the at least one output terminal (16 16a 16b) comprising one of a positive or a negative output terminal; a plurality of bus bars (28 28a 28b 28c 28d) configured to electrically connect the output terminals (16 16a 16b) of each of the plurality of batteries together, the plurality of bus bars (28 28a 28b 28c 28d) grouping the plurality of batteries into a plurality of battery units (42a 42b 42c 42d) each including at least two of the plurality of batteries, the plurality of bus bars (28 28a 28b 28c 28d) each configured to connect in parallel the output terminals (16 16a 16b) of the at least two of the plurality of batteries in a corresponding one of the battery units (42a 42b 42c 42d), and the plurality of bus bars (28 28a 28b 28c 28d) further configured to connect, in series, the plurality of battery units (42a 42b 42c 42d); characterized in that, the exhaust duct comprises at least one through-hole that connects inside and outside of the exhaust duct on a first wall surface facing a first bus bar on a respective at least one a gas distribution path, said at least one gas distribution path being formed from the valve portion to the first busbar through the through-hole of the exhaust duct, the at least one through-hole being arranged in a first direction, said first direction being perpendicular to the stacking direction, and in which the valve portion and the at least one output terminal (16 16a 16b) are arranged and, a metal filter disposed on the at least one gas distribution path and, the metal filter is comprised in a first plurality of metal filters corresponding to a first plurality of gas distribution paths, disposed in the stacking direction of the plurality of batteries, over a range corresponding to batteries belonging to a first terminal group of a first battery unit (42a 42b 42c 42d), to which a first bus bar of the plurality of bus bars (28 28a 28b 28c 28d) is fixed, and each metal filter of the first plurality of metal filters is disposed on a corresponding gas distribution path.