PROBLEM TO BE SOLVED: To provide a plant irradiation light irradiation device unit, which is wider than the directivity angle of a light emitting diode alone and has a small decrease in irradiance, and which is suitable for plant growth. SOLUTION: A plant growth light irradiation device unit includes a flat base body 1, a base body cover 2 having a cylindrical shape and capable of holding a thickness surface of the base body inside thereof, and a light emitting diode 3 installed on one surface of the flat base surface of the base body. And a drive circuit 6 for driving the light emitting diode and a reflector using four wire rods installed on the open surface of the base cover substantially parallel to the flat surface of the base on the light emitting diode installation side of the base cover 2 On the light emitting diode side of the holding portion 4 and the reflection plate holding portion, there is formed a reflection plate 5 installed so as to intersect the light emission center direction of the light emitting diode, and a satin-shaped 5b is formed on the surface of the reflection plate. [Selection diagram] Figure 1【課題】発光ダイオード単独の指向角より広く、放射照度の低下の少ない、植物育成に適した植物育成用光照射装置ユニットを提供する。【解決手段】植物育成用光照射装置ユニットは、平板の基体１と円筒状でその内面に基体の厚み面を保持できる基体カバー２と前記基体の平板面の一方の面に設置した発光ダイオード３と発光ダイオードを駆動させる駆動回路６と基体カバー２の発光ダイオード設置面側の基体の発光ダイオード設置側の平板面と略平行な基体カバーの開放面に設置した４本の線材を用いた反射板保持部４と反射板保持部の発光ダイオード側で、発光ダイオードの発光中心方向と交差するように設置した反射板５からなり、反射板の表面には梨地状５ｂが形成されている。【選択図】図１
