SEMICONDUCTOR LIGHT EMITTING DEVICE

A semiconductor light emitting device is provided to improve the reliability without the degradation of optical and electrical characteristics by restraining the generation of an interfacial delamination between a metal line and an adhesive using an improved through hole structure. A semiconductor light emitting device includes at least one semiconductor light emitting element(14), a mount substrate with a recess for mounting the semiconductor light emitting element, an insulating substrate(1a,1b) with a first through hole(4a) for forming an inner peripheral portion of the recess, an adhesive sheet(2) with a second through hole(4b) for forming the inner peripheral portion of the recess, a metallic reflection surface, a metal pattern, and a sealing resin part. The adhesive sheet is interposed between the mount substrate and the insulating substrate. The metallic reflection surface is partially formed on the inner peripheral portion of the recess. The metal pattern(9a,9b) is formed in the recess to be electrically connected with the semiconductor light emitting element. The sealing resin part(16) is used for sealing the semiconductor light emitting element. At least a portion of the second through hole is exposed to the sealing resin part. The width of the second through hole is smaller than that of the first through hole.