A light guide is arranged between a light source and a section for illumination disposed not directly in front of the light source to introduce light irradiated from the light source onto the section for illumination. The light guide includes an incident surface disposed in front side of the light source, a light distribution surface disposed behind the section for illumination, and a reflection surface opposed to the light source. The reflection surface reflects the light transmitted through the incident surface onto an area within a given angular range around the light source. The light reflected from the reflection surface is directed onto the light distribution surface. The light guide can efficiently utilize light from a light source as illumination.