A backlight unit (110) according to the present invention includes: a light source (102) for emitting light; a light guiding member (103) for receiving light emitted from the light source (102) at an end face (103c), and propagating the received light in a first direction (P); a prism sheet (104) disposed at the front face (103a) of the light guiding member (103); and a reflection section (105) disposed at the rear face (103b) side of the light guiding member (103), and the reflection section (105) has a reflection surface (105a) for light being emitted from the rear face (103b) of the light guiding member (103) and having a component in the first direction, the light being reflected toward the rear face (103b) of the light guiding member (103) as light having a component in a second direction which is the opposite direction to the first direction.