A backlight unit (3) provided with a LED package (light source) (11) and a light guide plate (14) includes a light-emitting portion (12) that is provided on the light guide plate side of the LED package (11) so as to be opposed to an incident surface (14a) of the light guide plate (14) and outputs light from the LED package (11) toward the light guide plate (14). A dimension on the incident surface side of the light-emitting portion (12) in a thickness direction of the light guide plate (14) is not more than a dimension at the incident surface (14a) of the light guide plate (14) in its thickness direction, and the light-emitting portion (12) uses a two-dimensional photonic crystal (12a).