PROBLEM TO BE SOLVED: To safely sterilize a sterilization chamber or an object to be sterilized in the sterilization chamber under atmospheric pressure.SOLUTION: A sterilization device includes: a sealable vessel (1) for accommodating liquid nitrogen oxide spaces (3, 3) to be sterilized which are kept under substantial atmospheric pressure a jetting device (2) for jetting the liquid nitrogen oxide into the spaces (3, 3) to be sterilized, and gasifying the jetted nitrogen oxide and quantitative pumps (4, 4) for supplying a predetermined amount of liquid nitrogen oxide from the vessel (1) to the jetting device (2). The sterilization device completely kills and destroys microorganisms including bacteria and viruses adhering to the spaces (3, 3) to be sterilized or a sterilization object accommodated in the spaces (3, 3).
