A light guiding plate guides light from a light source and irradiates the light onto a display portion. The light guiding plate has an exit plate facing the display portion, and a reflection-exit plane opposite to the exit plane. The reflection-exit plane has a first end intersecting an incidence plane and a second end intersecting an opposite end plane. An inclination angle, defined by the exit plane and a line that contains the first end and the second end, is greater than 0.20 and less than 0.75. The reflection-exit plane includes a light admission portion that reflects light entering through or reflected on the incidence plane to the exit plane.