possible to prevent the leakage of light therefrom accordingly the efficiency of using light can be enhanced as the synthetic resin 12 having refractive index which is substantially equal to that of glasses is molded on the surface of the protruding portion 5 of the first transparent substrate 2 so as to cover the light emitting diode chips 8 and the end face 3 a of the second transparent substrate 3 the light emitting diode chips 8 are shut off from the atmosphere so that the durability can be enhanced and further a quantity of light which is sent from the light emitting diode chips 8 to the second transparent substrate 3 can be increased as the end face 3 a of second transparent substrate 3 is formed into a surface having fine irregularities like a polished surface of glass a quantity of the light emitted from each light emitting diode chip 8 at each incident position are scattered and made even accordingly the back light can be distributed uniformly in addition as the terminal electrodes 10 and 11 used for supplying electric power to the light emitting diode chips 8 are arranged on the surface of the protruding portion 5 of the first transparent substrate 2 in such a manner that they are placed sideways in parallel to the terminal electrodes 7 for the transparent.