A method for plasma sterilization within a controlled temperature range includes exposing the interior of a chamber and any articles therein to a gas plasma flowing from a plasma generating chamber until the temperature in the chamber rises to a preselected maximum temperature. The flow of the plasma gas to the chamber is terminated when the temperature in the chamber falls to a temperature below the preselected maximum temperature. These steps are repeated until sterilization of the interior of the chamber or any articles therein is effected. The temperature below the preselected maximum temperature when gas plasma flow is again initiated is preferably not more than 3.degree. C. below the preselected maximum temperature. The gas plasma can be generated from a gas mixture that includes oxidizing and/or reducing agents. Preferably the pressure in the sterilizing chamber rises to from 0.1 to 10 torr when the gas plasma is flowing into the chamber, and the pressure in the sterilizing chamber falls to a lower pressure when the gas plasma flow into the sterilizing chamber is terminated. The articles to be sterilized include the interior of a vessel or chamber. The vessel or chamber itself serves as a sterilizing chamber and connects to the plasma generating chamber.