PROBLEM TO BE SOLVED: To provide an ultraviolet sterilization method and an ultraviolet sterilization device capable of effectively conducting ultraviolet sterilization on a liquid containing organic products, for example vegetable juice without deteriorating flavor thereof.SOLUTION: When sterilization is conducted by irradiating ultraviolet to a liquid to be sterilized consisting of a solution or a dispersion containing organic products, ultraviolet ray in a wavelength range of 253 nm to 280 nm is selectively irradiated to the liquid to be sterilized without contacting the liquid to be sterilized which exists in an area in which the ultraviolet ray is irradiated with an optical catalyst substance. At this time, the ultraviolet ray is irradiated from one direction or two directions opposing each other, and further width of an optical axis direction of the ultraviolet ray irradiated in the area is preferably set at a width with that the ultraviolet ray is irradiated to all of liquid to be sterilized existing in the area.SELECTED DRAWING: Figure 2【課題】 例えば野菜ジュースなどの有機物を含む液体に対して、その風味を損なうことなく効率的に紫外線殺菌を行うことが可能な紫外線殺菌方法及び紫外線殺菌装置を提供する。【解決手段】 有機物を含有する溶液又は懸濁液からなる被殺菌液体に紫外線を照射して殺菌を行うに際して、紫外線が照射される領域に存在する前記被殺菌液体を光触媒物質と接触させることなく、前記被殺菌液体に２５３ｎｍ以上２８０ｎｍ以下の波長領域の紫外線を選択的に照射する。このとき、紫外線は１方向又は互いに対向する２方向から照射し、更に前記領域における照射される紫外線の光軸方向の幅を、当該領域に存在する全ての被殺菌液体に前記紫外線が照射されるような幅とすることが好ましい。【選択図】図２
