A light-emitting device mounting package includes a substrate, a lead pin supported on the substrate, and an insulating member having a facing front surface which faces the front surface of the substrate and a facing back surface. The substrate has a first through hole and the ceramic plate has a second through hole. The lead pin has a shaft portion which penetrates the first and second through holes, a head portion provided at one end of the shaft portion, and a collar portion which extends from the shaft portion in the radial direction. The lead pin is fixed, via the collar portion, to a region of the facing back surface of the ceramic plate around an opening of the second through hole, and the ceramic plate is fixed to a region of the front surface of the substrate around an opening of the first through hole.