A mains electricity (AC-powered) device designed for terminal sterilization and/or inactivation of microorganisms from medical devices and related products using a combination of vaporized hydrogen peroxide (H2O2) and ozone gas as the sterilizing agent; it is typically used for products sensitive to high temperature and humidity. It typically includes a treatment chamber with shelves where the devices to be sterilized are placed, usually after cleaning of gross debris; a means to introduce the gas into the chamber; and controls to chose one of the sterilization cycles. The device is available as a stand-alone (bulk) unit.