In a flow-through compact sterilization apparatus (1) by a soft hydrothermal process, steam is circulated through a pressure vessel (3) in a state of highly saturated steam whose vapor saturation level is not less than 100%, and sterilization Perform high-pressure steam sterilization process by soft hydrothermal process which sterilizes things. In the high-pressure steam sterilization step, steam of a predetermined pressure and temperature is supplied to the pressure vessel at a predetermined flow rate through a feed motor valve (23) maintained at a predetermined opening degree, and the downstream side of the pressure vessel (3) , The opening degree of the exhaust motor valve (33) is adjusted according to the internal pressure of the pressure vessel (3) so that the internal temperature and the internal pressure of the pressure vessel (3) are maintained at predetermined values, respectively . The drying time of the object to be sterilized after sterilization can be greatly shortened.ソフト水熱プロセスによる流通式の小型滅菌装置(1)では、水蒸気を、蒸気飽和度が100%を下回らない高飽和水蒸気の状態で、圧力容器(3)を経由して流通させて、被滅菌物を滅菌するソフト水熱プロセスによる高圧水蒸気滅菌工程を行う。高圧水蒸気滅菌工程では、所定の圧力および温度の水蒸気を、所定の開度に維持した給蒸モーター弁(23)を介して所定の流量で圧力容器に供給し、圧力容器(3)の下流側において、圧力容器(3)の内部圧力に応じて排気モーター弁(33)の開度を調整して、圧力容器(3)の内部温度および内部圧力がそれぞれ所定値に維持されるように制御する。滅菌後の被滅菌物の乾燥時間を大幅に短縮できる。
