A light emitting device, comprises a LED chip, and a case having an accommodating recession accommodating the LED chip, wherein the light emitting device emits light from an opening portion of the accommodating recession, the case is monolithically formed by injection molding of a resin composition preparing by mixing fine grains of specular reflection material and glass fibers as diffusion reflecting material as fillers therein, an inner surface of a side wall portion of the case works as a reflector that reflects the light emitted from the LED chip so that the light is output from the opening portion, and a thickness of the side wall portion is selected to be smaller than an average length of the glass fibers.