PROBLEM TO BE SOLVED: To prevent defective sterilization in a steam sterilizer controlling a feed of steam for sterilization by a pressure inside a sterilizing tub.SOLUTION: In the steam sterilizer controlling the feed of steam for sterilization based on the pressure inside the sterilizing tub 1, a first temperature A calculated based on the pressure inside the sterilizing tub 1 and a second temperature B inside the sterilizing tub 1 detected by a temperature sensor are compared at the sterilization, and the sterilization time is adjusted based on the lower temperature among the first temperature A and the second temperature B.COPYRIGHT: (C)2002,JPO【課題】 滅菌槽内の圧力に基づいて滅菌用蒸気の供給を制御する蒸気滅菌装置において、滅菌不良を防止する。【解決手段】 滅菌槽1内の圧力に基づいて滅菌用蒸気の供給を制御する蒸気滅菌装置において、滅菌時、前記滅菌槽1内の圧力に基づいて算出した第一温度Aと、温度センサにより検出した前記滅菌槽1内の第二温度Bとを比較し、これらの第一温度Aおよび第二温度Bのうち低い方の温度に基づいて滅菌時間を調節する。