The method involves heating preforms (12) covered with sterilizing product upto a temperature at or above an activation temperature for the product. A flow of sterilizing vapor is sprayed in a protective chamber (40), and the sterilizing vapour is heated outside the protective chamber. The flow of sterilizing vapor in a form of a jet of vapor is vaporized onto the preforms to bring about deposition of a uniform film of condensate of the sterilizing product on an inner wall of the preforms to be sterilized. Atmosphere is extracted from the protective chamber. An independent claim is also included for a device for sterilizing a line of preforms made of plastics material that are intended to be molded, by blow molding.
