An illumination device (3) is provided with a light-emitting diode (light source) (9), and a light guide plate (10) that guides light from the light-emitting diode (9) toward a prescribed propagation direction and that outputs the light toward a liquid crystal panel (object to be irradiated) (2). The illumination device is also provided with an optical sheet (optical member) (15) that is disposed so as not to make contact with the optical sheet (13) and that separates the optical sheet (13) from the liquid crystal panel (2) so as to create a prescribed space therebetween.