PURPOSE: A plasma sterilizing method is provided to reduce the amount of used sterilization by injecting the germicide at a first pressure which is lower than atmospheric pressure. CONSTITUTION: A plasma sterilizing method which sterilizes bacteria by placing the bacterial inside a chamber comprises the following steps: injecting germicide in a chamber until the pressure becomes first pressure which is lower than the atmospheric pressure； injecting external air into the chamber until the pressure becomes second pressure which is higher than the atmospheric pressure； reducing pressure inside the chamber； and generating plasma in the chamber. [Reference numerals] (AA,CC) Temperature； (BB,DD) Pressure； (EE) Pre-heat temperature； (FF) Second pressure； (GG) Atmosphere； (HH) First pressure； (II) Third pressure； (JJ) Vacuum pressure； (KK) Start； (ST12) Preheat본 발명에 따른 플라즈마 멸균 방법은, 챔버 내부에 피멸균물을 위치시켜 상기 피멸균물을 멸균하는 플라즈마 멸균 방법으로서, 대기압보다 낮은 제1 압력이 될 때까지 챔버에 멸균제를 주입하는 단계； 대기압보다 높은 제2 압력이 될 때까지 상기 챔버에 외부 공기를 주입하는 단계； 상기 챔버 내부를 감압하는 단계； 및 상기 챔버에 플라즈마를 발생시키는 단계를 포함한다.
