The method and the device according to the invention are used to sterilize preforms (1) made of a thermoplastic material that are intended for producing blow-molded containers. During the sterilization, a sterilizing agent is introduced into the area of the preform (1). The sterilizing agent is discharged at least partially from at least one nozzle (44) in the direction of the preform (1). An average direction (45) of the escape of the sterilizing agent from the nozzle (44) is provided with an angle of inclination (46) from a longitudinal axis (47) of the preform (1).