The present invention relates to a method of sterilizing and/or sanitizing a container using a sterilant vapor such as hydrogen peroxide. The sterilant vapor is discharged through a nozzle positioned in an opening of the container and the container is then purged of the discharged sterilant using a heated gas such as sterile air. The nozzle is preferably positioned no closer than 15 mm from the bottom surface or any internal surface of the container and within 1/6 to 5/6 of the height of the container. The nozzle has a diameter no greater than one-half of the diameter of the opening of the container. When containers made of non-heat set PET are used, the temperatures of the sterilant vapor and the purge gas are preferably no greater than 160° F.