To provide a structure of a lighting system capable of improving luminance of illumination light and its uniformity.

This lighting system 10 is provided with a light source 11, a first light guide part 12 and a second light guide part 13. A first light emitting surface 12b is structured to further deflect an emitting angle distribution on a virtual plane of light emitted from the first light emitting surface to a high emitting angle side as a whole with respect to a direction crossing an optical axis by including an inclined surface inclined in a direction in which the light in the first light guide part propagates with respect to the optical axis on the virtual plane P parallel to a second emitting surface with respect to the optical axis 11x; and a second light entering surface 13a includes a light refracting structure refracting, to the vicinity of a direction orthogonal to the optical axis, the light obliquely emitted with respect to a direction F13 orthogonal to the optical axis on the virtual plane from the first light emitting surface.