The present invention relates to a sterilization method using a low-temperature sterilizing device, wherein: the low-temperature sterilizing device is configured so as to have therein a closed circuit including a sterilization space, a vacuum pump, and a tank, by using a valve that can be opened and closed； and the pressure inside the sterilization space is repeatedly changed by repeatedly performing a processes of discharging air inside the sterilization space by means of the vacuum pump and injecting air into the sterilization space by means of the tank. The pressure inside the sterilization space is repeatedly changed by means of an air circulation unit, a pressure difference is generated between the sterilization space and the inside of a sealing member, and a vaporized sterilizing agent infiltrates into the sealing member, through a process in which the air is injected into and discharged from the inside of the sealing member by the pressure difference, and sterilizes a sterilization target.
