BATTERY MODULE

A plate-shaped member (100, 200) includes a flat surface portion (150, 230), a flange portion (140, 220), and a transition portion (160, 240), the flange portion (140, 220) being provided at an end portion of the plate-shaped member (100, 200), the flange portion (140, 220) protruding from the flat surface portion (150, 230) in the first direction, the transition portion (160, 240) continuously transitioning from the flat surface portion (150, 230) to the flange portion (140, 220). The flat surface portion (150, 230), the transition portion (160, 240), and the flange portion (140, 220) are provided to be arranged side by side in the second direction.