To provide a light source module device capable of controlling the light distribution of ultraviolet light with a small and simple structure. A light source module device 7 includes a substrate 4, a light source 3 mounted on the substrate 4 and emitting ultraviolet light, a reflector 8 mounted on the substrate 4 so as to surround the light source 3 and reflecting the ultraviolet light by its inner surface to guide the ultraviolet light toward an irradiation target, and a cap-like optical member 9 mounted so as to cover the outer circumference of the reflector 8 and condensing or diffusing the ultraviolet light.