PROBLEM TO BE SOLVED: To provide a sterilization method of a packed beverage, which allows a container to be thinned and lightened and eliminates variation in sterilization effect resulting from ununiformity of the product temperature of the container in heat sterilization.SOLUTION: The sterilization method of a packed beverage includes the steps of: increasing the pressure in a pressure vessel within the range that the internal pressure of a container is higher than the pressure in the pressure vessel with a differential pressure between the internal pressure of the container and the pressure in the pressure vessel of not exceeding the limit pressure of the container, heating the interior of the pressure vessel up to a temperature required for sterilization, and then increasing the pressure in the pressure vessel to a predetermined maximum pressure.
