A light-emitting element mounting package comprising: - a substrate, - a plurality of individual package areas to be individual light-emitting element mounting packages as a result of dicing, which are longitudinally and laterally arranged on the substrate, wherein each of the areas includes: - a wiring (31, 32) that is provided on one surface of the substrate to form a light-emitting element mounting portion (31, 32, 41, 42), on which a light-emitting element is to be mounted; - a through wiring (51, 52) that penetrates the substrate and has one end and another end, the one end of the through wiring being electrically connected to the corresponding light-emitting element mounting portion so as to transfer heat, the another end protruding from another surface of the substrate; and - a reflection plate (81, 91) that is provided on the light-emitting element mounting portion (31, 32, 41, 42); the light-emitting element mounting package further comprising: - a frame portion (82, 92) provided to entirely surround the plurality of reflection plates (81, 91); and - hung portions (83, 93) for connecting the frame portion (82, 92) with the reflection plates (81, 91) adjacent to the frame portion (82, 92) and for connecting each reflection plate with another reflection plate mutually adjacent, wherein the reflection plate (81, 91) and the another reflection plate are arranged by interposing a predetermined interval therebetween, wherein the reflection plate, the another reflection plate (81, 91), the frame portion (82, 92), and the hung portion (83, 93) are integrally formed as a metallic member (80,90), wherein plating films (41, 42) cover the upper and side surface of the wiring, wherein a connecting portion of the plating films (41, 42) to be connected to an electrode of the light-emitting element is exposed through an opening portion formed in the reflection plate (81, 91), wherein plural reflection plates are longitudinally and laterally arranged while interposing a predetermined interval and the reflection plates are arranged on each light-emitting mounting portion inside each individual package area, wherein the light-emitting element is to be mounted inside the opening portion, and wherein the metallic member is adhered onto the plating films (41, 42) via an adhesive layer. - a substrate, - a plurality of individual package areas to be individual light-emitting element mounting packages as a result of dicing, which are longitudinally and laterally arranged on the substrate, - a wiring (31, 32) that is provided on one surface of the substrate to form a light-emitting element mounting portion (31, 32, 41, 42), on which a light-emitting element is to be mounted; - a through wiring (51, 52) that penetrates the substrate and has one end and another end, the one end of the through wiring being electrically connected to the corresponding light-emitting element mounting portion so as to transfer heat, the another end protruding from another surface of the substrate; and - a reflection plate (81, 91) that is provided on the light-emitting element mounting portion (31, 32, 41, 42); the light-emitting element mounting package further comprising: - a frame portion (82, 92) provided to entirely surround the plurality of reflection plates (81, 91); and - hung portions (83, 93) for connecting the frame portion (82, 92) with the reflection plates (81, 91) adjacent to the frame portion (82, 92) and for connecting each reflection plate with another reflection plate mutually adjacent,