The invention relates to a method and to a device for quickly decontaminating and sterilizing preferably thermolabile goods using a plasma gas that is preferably generated from air as a process gas, with the subsequent humidification of said plasma gas with water. The method comprises the following steps: generating a plasma from air as the process gas, which forms reactive nitrogen and oxygen species oxidizing NO to form NO2 at temperatures below 400° C. so that a plasma-activated gas mixture forms having an NO2 content of at least 0.3% bringing said plasma-activated gas mixture in contact with water in one or more of the states of aggregation thereof bringing the latter gas mixture in contact with the objects to be decontaminated or sterilized.