PROBLEM TO BE SOLVED: To provide a technique to efficiently operate a boiler and to quickly start a sterilizing motion by a steam sterilizer by employing a high-temperature steam injecting method for injecting high-temperature steam generated by the outside boiler to the inside of a chamber instead of using a structure to place a sterilizing heater at a bottom part of the chamber.SOLUTION: The steam sterilizer includes the boiler to generate high-temperature steam injected to the inside of the chamber by an electric heater and performs an exhaust and drying process of discharging air and drying the inside of the chamber after injecting the high-temperature steam to the inside of the chamber from the boiler upon the start of a sterilizing mode to perform a sterilizing process on an article to be sterilized inside the chamber in the high-temperature steam. The steam sterilizer is equipped with an energy-saving mode and a speed mode. In the energy-saving mode, the steam sterilizer puts the power distribution of the electric heater in an OFF state at the end of the sterilizing process until the end of the operation of the sterilizing mode, and in the speed mode, the steam sterilizer puts the power distribution of the electric heater in a prescribed heat generating state at the end of the sterilizing process by controlling to turn ON/OFF until the end of the operation of the sterilizing mode.COPYRIGHT: (C)2012,JPO&INPIT【課題】チャンバの底部に滅菌ヒータを配置する構成に替えて、外部のボイラで発生させ高温蒸気をチャンバ内へ注入する高温蒸気注入方式とすることによって、ボイラの効率的な運転を行なうことと、速やかに蒸気滅菌器による滅菌動作の開始ができる技術を提供する。【解決手段】電気ヒータによってチャンバ内へ注入する高温蒸気を発生させるボイラを備え、滅菌モードの開始によって、ボイラから高温蒸気をチャンバ内へ注入し、チャンバ内の被滅菌物を高温蒸気下で滅菌工程を実行した後、チャンバ内を排気乾燥する排気乾燥工程を実行する蒸気滅菌器において、省エネモードとスピードモードを備え、省エネモードでは、滅菌工程の終了にて電気ヒータの通電を滅菌モードの運転終了までOFF状態とし、スピードモードでは、滅菌工程の終了にて電気ヒータの通電を滅菌モードの運転終了までON・OFF制御にて所定発熱状態とすること。【選択図】図1