PROBLEM TO BE SOLVED: To irradiate UV-B light in a wide range and as homogeneously as possible even when installed at a relatively low height, and yet to suppress excessive UV-B light irradiation to a plant directly below. Provided are a lighting device for plants and a lighting device for plants. A lighting device for plants of the present invention is arranged on one side in a first direction with respect to a light source that emits UV-B light, and the UV-B light is placed on the other side in the first direction. The first reflecting member that guides the light source is disposed on the opposite side of the first reflecting member in the first direction so as to sandwich the light source, and a part of the received UV-B light is partially reflected by the first reflecting member. And the second reflecting member that guides the other part of the received UV-B light to the back side while guiding the other side. [Selection diagram]【課題】比較的低い高さに設置しても広範で可能な限り均質にUV-B光を照射でき、それでいて直下の植物に対しても過度にUV-B光が照射されることを抑制可能な植物用照明器具及び植物用照明装置を提供する。【解決手段】本発明の植物用照明器具は、UV-B光を照射する光源に対して第1方向における一方の側に配置され、前記UV-B光を前記第1方向における他方の側に導く第1反射部材と、前記光源を挟むように前記第1方向に関して前記第1反射部材とは反対側に配置され、受光した前記UV-B光のうちの一部を前記第1反射部材の側へ導くとともに、前記受光したUV-B光のうちの他部を裏側へ導く前記第2反射部材と、を含む。【選択図】 図1