A battery module includes a cell stack having pouch-type battery cells provided to stand side by side and stacked in a horizontal direction, and a module housing configured to accommodate the cell stack. The module housing includes a lower plate provided in a rectangular plate form to support the cell stack at a lower portion of the cell stack; and a first left pressing plate and a first right pressing plate having elasticity and extending upwards at both side edge regions of the lower plate, which are provided side by side, to form an acute angle with respect to a vertically upper direction so that a gap between the first left pressing plate and the first right pressing plate becomes narrowed upwards. The first left pressing plate and the first right pressing plate are elastically biased to press both side surfaces of the cell stack.