A battery module case includes: a first case in which a plurality of first battery cells is held in a stacked state and which includes a first plate formed with a first cutout portion from which an end surface of one of the first battery cells which is adjacent to the first plate is exposed; and a second case in which a plurality of second battery cells is held in a stacked state and which includes a second plate confronting the first plate and formed with a second cutout portion from which an end surface of one of the second battery cells which is adjacent to the second plate is exposed. When the first and the second plates are arranged adjacent to each other, the first cutout portion and the second cutout portion define a passage in which cooling fluid can flow between the first plate and the second plate.