A backlight (2) (illumination device) of this invention includes: a plurality of light sources (5), a plurality of light guide bodies (7) for causing surface emission of light emitted from the light sources; a diffusing plate (8) (flat plate) provided so as to face light-emitting surfaces (7a) of the light guide bodies (7) while maintaining a predetermined distance between the diffusing plate (8) and the respective light-emitting surfaces (7a). Maintaining sections (10) (distance maintaining sections) are provided between the respective light guide bodies (7) and the diffusing plate (8) and provided on the side of the diffusing plate (8), the maintaining sections (10) maintaining the predetermined distance between the diffusing plate (8) and the respective light-emitting surfaces (7a) of the respective light guide bodies (7).