A battery module includes a cell stack in which a plurality of unit cells including terminal parts are aligned in a first direction and an insulating member surrounds the plurality of unit cells; and a module housing in which a plurality of receiving parts, into each of which the cell stack is configured to be inserted, are provided and are aligned in a first direction and a second direction perpendicular to the first direction, wherein each of the plurality of receiving parts includes a fixing wall around the cell stack and having at least a portion which is in contact with the cell stack. The cell stacks adjacent to each other in the second direction are electrically connected to each other, and the cell stacks adjacent to each other in the first direction are electrically disconnected from each other, when not connected to an end module.