To provide a light radiation device which effectively extracts light emitted from an ultraviolet light emitting element and realizes high ultraviolet radiation energy.

A light radiation device includes a light emitting element 20 housed in a through hole 12 of a substrate 10. The substrate 10 has: a first substrate 10a having first through holes 12a; a pair of second substrates 10b disposed on both surfaces of the first substrate 10a and each having a second through hole 12b, which is wider than the corresponding first through hole 12a; and a first power supply circuit 40a and a second power supply circuit 40b. The light emitting element 20 has a base substrate 21, a semiconductor layer 22, and a first electrode 23 and a second electrode 24 and is bonded to inner walls of the first through holes 12a through a heat conductive adhesive 50. The first power supply circuit 40a is connected with the first electrode 23 through a first metal wire 15a and the second power supply circuit 40b is connected with the second electrode 24 through a second metal wire 15b.