Provided is a novel container sterilization method in which no liquid agent is used. A container sterilization method is a method of performing sterilization by supplying a sterilization component to a container that is continuously conveyed along a predetermined conveyance path, the container sterilization method including supplying a humid ozone gas to a sterilization area, the humid ozone gas being an ozone gas that has humidity, the sterilization area being partitioned by a sterilization chamber that contains the conveyance path. It is preferable that the humid ozone gas to be supplied to the sterilization area have a higher temperature than the container to be conveyed to the sterilization area and the sterilization chamber have a higher temperature than the container to be conveyed to the sterilization area.