FLUID STERILIZATION DEVICE

The purpose of the present invention is to provide a fluid sterilization device which is capable of effectively utilizing wide-angle ultraviolet light that is irradiated from a light source unit, and which causes a fluid to remain in an ultraviolet light irradiation range, while having an extremely simple structure. A fluid sterilization device according to the present invention is characterized by comprising: a first flow path part which extends in the axial direction and has a fluid flow therethrough from one end to the other end; a light source unit which is connected to the other end of the first flow path part and irradiates the fluid with ultraviolet light; a second flow path part which faces the first flow path part, with the light source unit being interposed therebetween; and a third flow path part which is arranged outside the light source unit in the radial direction so as...