A backlight device (3) is provided with: a reflective sheet (8) that reflects light from a light guide plate (7) back towards the light guide plate (7); a bottom (opposing surface) (10a) that is arranged so as to face the reflective sheet (8) on the side of the reflective sheet (8) opposite to the light guide plate (7) and that has a prescribed squeezing part (a part with recesses and protrusions) (10a1) formed thereon; and a cushioning member (9) arranged between the reflective sheet (8) and the bottom (10a). The cushioning member (9) has an opening (9a) at a location that corresponds to the squeezing part (10a1).