PROBLEM TO BE SOLVED: To provide a sterilization method capable of ultraviolet sterilization with high certainty to bacterial cells to be sterilized low in ultraviolet permeability such as foods or drinks without reducing flavor or quality thereof, capable of practically omitting cleaning operation of an ultraviolet permeable window material in an ultraviolet irradiation device and further less in risk of re-contamination.SOLUTION: By selectively irradiating ultraviolet in a wavelength range of 253 nm to 280 nm surely to bacterial cells to be sterilized in a container from outside of the container through an ultraviolet permeation part after filling the bacterial cells to be sterilized in a container having the ultraviolet permeation part having uniform thickness such as a plastic bag by making a bag from an ultraviolet permeable film consisting of a heat sealing resin for example, the container in which the bacterial cells to be sterilized are filled from completion of the filling to completion of ultraviolet irradiation is air tightly sealed or the encapsulation is conducted under same sterile environment as time for ultraviolet irradiation.SELECTED DRAWING: Figure 1【課題】 たとえば、食品や飲料などのように紫外線透過率が低い被殺菌体に対して、その風味や品質を低下させることなく、確実性の高い紫外線殺菌が可能で、紫外線照射装置における紫外線透過性窓材の清浄化作業を実質的に省略でき、更に再汚染の危険性が少ない殺菌方法を提供する。 【解決手段】 たとえばヒートシール性樹脂からなる紫外線透過性フィルムを製袋してなる可撓性袋などのような、均一の厚さを有する紫外線透過部を有する容器に被殺菌体を充填した後に、該容器の外部から、前記紫外線透過部を通して、容器内部の被殺菌体に確実に２５３ｎｍ以上２８０ｎｍ以下の波長領域の紫外線を選択的に照射するようにし、更に前記充填が終了してから紫外線照射が終了するまでの間に被殺菌体が充填された容器を気密に封止するか、又は紫外線照射時と同一の無菌環境下で前記封止を行う。【選択図】 図１
