An object of the present invention is to provide a highly innovative photocatalytic reaction device that has never existed before. A photocatalytic reaction device for irradiating a photocatalyst with ultraviolet rays to cause a photocatalytic reaction, wherein a container 1 having a fluid passage space S through which a fluid is passed is irradiated with ultraviolet rays, and an ultraviolet ray irradiation source 2 is provided. A light receiving portion 3 for receiving the ultraviolet light emitted from the light source 2 is provided, a light receiving surface 3a of the light receiving portion 3 is provided so as to face the ultraviolet light irradiation source 2, and the light receiving surface 3a is provided with the photocatalyst. 4 is provided, and the light receiving surface 3a is a concave curved surface. [Selection diagram] Figure 1【課題】本発明は、従来にない非常に画期的な光触媒反応装置を提供することを目的とする。【解決手段】光触媒に紫外線を照射して光触媒反応を生じさせる光触媒反応装置であって、流体を通過させる流体通過空間Ｓを有する容体１に、紫外線を照射する紫外線照射源２と、この紫外線照射源２から照射される紫外線を受光する受光部３とが設けられ、この受光部３の受光面３ａは前記紫外線照射源２と対向するように設けられ、更に、前記受光面３ａには前記光触媒４が設けられ、また、前記受光面３ａは凹湾曲面である。【選択図】図１
