A liquid crystal display device (1) of the present invention includes a display panel (3) and a backlight (2) (an illumination device). The backlight (2) includes a light-emitting layer (20) in which a plurality of light sources (5) are scattered and a diffuser (7) (a diffusion layer) that is formed on the light-emitting layer and diffuses light from the light-emitting layer. The light sources (5) that are present within the light-emitting layer (20) emit light in a direction (a direction of an arrow) substantially parallel to a boundary surface between the light-emitting layer (20) and the diffuser (7). In the diffuser (7), a transmittance of light in an area (7c) close to each of the light sources is smaller than a transmittance of light in an area that is far from each of the light sources.