To provide a display device for controlling the angle of diffusion (irradiation range) of a light beam made to exit from a light source, and for irradiating the irradiation range with averaged light intensity.

The display device is provided with: a light source 1; a display element 5 for generating an image, and for illuminating a generated image with a luminous flux made to exit from the light source; and an optical element 3. The optical element is provided with a rear face 3a on which the luminous flux from the light source is made incident, a side face 3c from which a portion of the luminous flux made incident form the rear face is reflected and a front face 3b through which the luminous flux made incident from the rear face including the luminous flux reflected from the side face is refracted or straightly advances and exits to the display elements. The display element is arranged so that the peripheral region of the display element can be illuminated with the luminous flux components made incident from the rear face of the optical element, reflected from the side face and exiting from the front face together with the luminous flux components made incident from the rear face of the optical element and directly exiting from the front face.