The present invention expands, by using a surface-area expansion means (30), the surface area of a stabilized chlorine dioxide solution (10) which is irradiated with ultraviolet rays (71) and stored in a storage tank (20), quickly generates a chlorine dioxide gas, and discharges the gas to the exterior of the vessel by using a ventilation means (61). The chlorine dioxide gas is stably discharged by irradiating the stabilized chlorine dioxide liquid with ultraviolet rays. It is possible to adjust the concentration of the generated chlorine dioxide gas by adjusting the concentration of the stabilized chlorine dioxide solution (10) and the ultraviolet ray (71) output. By directly discharging a low-concentration chlorine dioxide gas that is safe for people into the interior of a room in which people live, it is possible to sterilize the interior of the room from corner to corner. When the concentration thereof is high, it is possible to sterilize a medical device inside a medical-device sterilization box. As a result, it is possible to provide a chlorine-dioxide-gas generation device which makes it possible to quickly and sustainably generate chlorine-dioxide gas and easily manage the concentration of the chlorine-dioxide gas.La présente invention étend, en utilisant un moyen d'extension de surface (30), la surface d'une solution de dioxyde de chlore stabilisée (10) qui est irradiée avec des rayons ultraviolets (71) et conservée dans un réservoir de stockage (20), génère rapidement du dioxyde de chlore gazeux et libère le gaz à l'extérieur du récipient en utilisant des moyens de ventilation (61). Le dioxyde de chlore gazeux est libéré de manière stable en irradiant avec des rayons ultraviolets le dioxyde de chlore liquide stabilisé. Il est possible d'ajuster la concentration du dioxyde de chlore gazeux généré en ajustant la concentration de la solution de dioxyde de chlore stabilisée (10) et la puissance des rayons ultraviolets (71). En libérant directement du dioxyde d
