The light-emitting device 1 has a translucent cover 10 having a cylindrical shape and a flat light-projecting surface 11 facing to the light-emitting part of an LED 20. The LED 20 is arranged in close proximity with the flat light-projecting surface 11 in the translucent cover 10 to achieve efficient introduction of light from the LED 20 into a light-receiving surface of optical fibers.
