Abstract: The method for producing dinitrogen tetraoxide comprising the steps of operating a decompressor (3) to reduce a pressure within the space area (2) maintained in the hermetically sealed condition to the decompressed or vacuum condition below the saturated vapor pressure curve of dinitrogen tetraoxide, supplying the dinitrogen tetraoxide liquid as a sterilant feedstock from a vessel (4) to a spray device (25) while preventing gasification of the dinitrogen tetraoxide liquid on the way between the vessel (4) and spray device (25), and spraying the dinitrogen tetraoxide liquid through the spray device (25) into the space area (2) under the decompressed or vacuum condition to, at the time of the spraying, gasify at least some of the dinitrogen tetraoxide liquid within the space area (2) decompressed below the saturated vapor pressure curve.

Abstract: Nitrogen oxide is used to safely sterilize inside of a space area or an object arranged within the space area. A sterilization method is provided to comprise: introducing nitrogen oxide liquid stored in a vessel (4) into a space area (2, 2?, 2?) to gasify nitrogen oxide liquid, and sterilizing inside of space area (2, 2?, 2?) or object (1) arranged in space area (2, 2?, 2?) with nitrogen oxide gas evaporated from nitrogen oxide liquid to completely annihilate and destroy microorganisms inclusive of bacteria and virus with nitrogen oxide gas for preventing the infection by microorganisms to human body and damage to precision components.

Abstract: Nitrogen oxide is used to safely sterilize inside of a space area or an object arranged within the space area. A sterilization method is provided to comprise: introducing nitrogen oxide liquid stored in a vessel (4) into a space area (2, 2?, 2?) to gasify nitrogen oxide liquid, and sterilizing inside of space area (2, 2?, 2?) or object (1) arranged in space area (2, 2?, 2?) with nitrogen oxide gas evaporated from nitrogen oxide liquid to completely annihilate and destroy microorganisms inclusive of bacteria and virus with nitrogen oxide gas for preventing the infection by microorganisms to human body and damage to precision components.