A plurality of prisms 23e which make an input angle of light from an LED 21 with respect to a rear surface of a light guiding body 23 gradually small are provided on a light emission plane 23b of the light guiding body 23, and a plurality of prisms 24b which cause the light from the LED 21 to be totally reflected to front in an interface between a rear surface of a low refractive index layer 24 and an air layer are provided on the rear surface of the light guiding plate 22. The light guiding plate 22 further includes an inclined plane 30 which is inclined to an optical axis O of the light from the LED 21. The inclined plane 30 is configured so as to cause input light to be reflected in the direction which is close to the optical axis O.