A method of manufacturing a light emitting device having a resin package which provides an optical reflectivity equal to or more than 70% at a wavelength between 350 nm and 800 nm after thermal curing, and in which a resin part and a lead are formed in a substantially same plane in an outer side surface, includes a step of sandwiching a lead frame provided with a notch part, by means or an upper mold and a lower mold, a step of transfer-molding a thermosetting resin containing a light reflecting material in a mold sandwiched by the upper mold and the lower mold to form a resin-molded body in the lead frame and a step of cutting the resin-molded body and the lead frame along the notch part.