<p><P>PROBLEM TO BE SOLVED: To provide an illumination device for plant cultivation which can efficiently radiate heat generation of a semiconductor light emitting device, and can be inexpensively manufactured, and to provide a plant cultivation device using the illumination device for plant cultivation. <P>SOLUTION: The illumination device for plant cultivation 10 includes: a light emitting part 11 equipped with a rectangle heat conductivity substrate provided with projecting parts continued in a longitudinal direction and integrally molded on one side surface, a plurality of light emitting members mounted on the projecting parts, and a wiring substrate provided adjacently to the projecting parts and provided with a wiring for supplying power to the plurality of light emitting members on one side surface of the heat conductivity substrate; and a reflection part 12 which partially contacts the other side surface of the heat conductivity substrate and causes the light radiated by the plurali
