Even for a diseased part that is not flat, which is suitable for treatment of a relatively small diseased part, substantially uniform and efficient light irradiation is realized for the entire affected part. The light emitted from the plurality of LED chips (5) has a first wavelength range light having a peak of emission intensity in a wavelength range of 380 nm or more and 430 nm or less, a second wavelength range light having a longer wavelength than 430 nm, a light emission intensity And a second wavelength region light having a peak, and the LED light source group has uniform in-plane light irradiation intensity.比較的小さな疾患部の治療に適した、平坦では無い患部に対しても、患部全体に対してほぼ均一で効率的な光照射を実現する。複数のLEDチップ(5)が出射する光は、380nm以上430nm以下の波長範囲に発光強度のピークを有する第1波長域光と、430nmよりも波長が長く、635nm以下の波長範囲に発光強度のピークを有する第2波長域光とを含んでおり、LED光源群は面内光照射強度が均一である。
