A substrate includes a storage portion which is defined by a base for mounting a light emitting element and a wall portion standing up on and from the base. A package is structured such that the upper end of the wall portion so formed as to surround the periphery of the storage portion is connected to a cover to thereby seal a light emitting element. A seal structure is composed of an uneven portion formed on the lower surface side surface of the base, a close contact layer formed on the surface of the uneven portion, a power supply layer formed on the close contact layer, and an electrode layer formed on the surface of the power supply layer. The uneven portion includes a first recessed portion formed at a position spaced in the radial direction from the outer periphery of a through electrode or from the inner wall of a through hole, and a second recessed portion formed at a position spaced further outwardly from the first recessed portion.