PROBLEM TO BE SOLVED: To solve the problem in which an ultraviolet irradiation member generates heat by supplied power or the like, but a countermeasure against heat generation is still insufficient.SOLUTION: An ultraviolet irradiation unit includes a holding member, an ultraviolet irradiation member being held by the holding member and irradiating an ultraviolet ray to a fluid to be processed, and a temperature detection part being provided on the holding member and detecting temperature information related to a temperature of the ultraviolet irradiation member.SELECTED DRAWING: Figure 1【課題】供給された電力等によって紫外線照射部材が発熱するが、これらの発熱に対する対策がまだ十分でない。【解決手段】紫外線照射ユニットは、保持部材と、前記保持部材に保持され、被処理流体に紫外線を照射する紫外線照射部材と、前記保持部材に設けられ、前記紫外線照射部材の温度に関する温度情報を検出する温度検出部と、を備える。【選択図】図１
