A sterilization system comprises a reaction container configured to receive a sterilization object and sterilize the object； means for supplying peracetic acid as an sterilization agent into the reaction container, the peracid agent including at least peracetic acid； means for reducing a pressure in the reaction container； means for ventilating the reaction container； and means for generating plasma at a first predetermined portion for receiving the sterilization object in the reaction container and a second predetermined portion of a fluid passage from a neighborhood of the first predetermined portion to an exterior of the container. The pressure reducing means and the plasma generating means are controlled so that the plasma is maintained at the predetermined portions in a process during which the pressure in the reaction container is reduced.
