Method of sterilization of a medical device, in particular surgical instrument, placed in a closable airtight container, including placing such medical device inside a closable airtight container; closing the container; placing a Vacuum Ultraviolet Light source against a window of said container, wherein such window is transparent to Vacuum Ultraviolet light and to UVC and/or Middle Ultraviolet light; irradiating a volume inside such closed container with Vacuum Ultraviolet Light through such window in order to generate ozone and/or ozonites within such volume; removing the Vacuum Ultraviolet Light source; and waiting for an incubation time.