Abstract: At a position opposite to a first board 130(a) supporting a fist light-emitting diode group 131 which has light-emitting portions on the same side and is arranged annularly surrounding a light-delivering hole, a concave mirror 150(a) is located so that the focal point thereof would be formed at the position of the light-delivering hole. Behind the concave mirror 150(a), a second board 140 supporting a second light-emitting diode group 141 is located. Light beams emitted from the first light-emitting diode group 131 are reflected by the concave mirror 150 (a) and collected on an optical connector 181, and light beams emitted from the second light-emitting diode group 141 are allowed to pass through a hole formed at the center of the concave mirror 150(a) and directly collected on an optical connector 181. To the optical connector 181, an optical fiber cable as a light guide is connected to form a light source of illumination for a light guide 100.