PURPOSE: To provide an illuminator where numbers of LED(light emitting diode) pellets are closely arranged, and which obtains high projected light quantity is specified range and is easy to be assembled and uses light emitting diode array suitable for mass production.

CONSTITUTION: A wiring board 1 where plural light emitting diode pellets 2 are disposed in a longitudinal direction and a case 4 where light guide pores 8 facing to the light radiation surfaces of respective light emitting diode pellets 2 are bored are aligned by taking a mark formed on respective side surfaces and the light emitting diode pellet 2 as the mark and are integrated. Thus the wiring board 1 and the case 4 are accurately aligned at a specified position, so that light radiation effeciency is improved. Then, the case is made divisible, and in the case of forming number of light guide pores 8, they are molded without requiring boring operation, so that the illuminator is easily and rapidly produced without requiring a skillfull operator and the mass production is attained, thereby reducing the cost.