Provided is a sterilization device for a container which exhibits high sterilization performance while being low in cost. A heating medium is positioned in a sterilant passage so as to block the downstream end thereof in the direction in which the liquid sterilant is discharged. A ventilation passage is formed in the lateral surface of a tube body of a sterilant supply tube, on the upstream side in the direction in which the liquid sterilant is discharged in relation to the heating medium. A sterilant supply unit sterilizes the inner-peripheral surface of a container as a result of the sterilant vaporizing upon reaching the heating medium, leaking to the exterior via the ventilation passage formed in the lateral surface of the tube body, and adhering to the inner-peripheral surface of the container.
