PURPOSE: To perform an inspection and repair without totally interrupting a packaging work even when a trouble is generated by constituting a sterilizing device to sterilize a packaging film of a storage tank and first and second sterilizers.

CONSTITUTION: A sterilizing device 1 is constituted of a storage tank 2 which has sterilizing lamps 2a, 2b inside, a plurality of feeding rollers 7, 7a-7c to feed a packaging film 3a, and first and second sterilizers 4, 5. At the time of packaging work of a liquid food, a liquid food 2c which is sterilized by the sterilizing lamps 2a, 2b in the storage tank 2 is fed to a location where the second sterilizer 5 is provided, through a feeding tube 6. Then, the liquid food 2c is packaged with the packaging film 3a which is sterilized when passing through the first sterilizer 4. The first sterilizer 4 is constituted of a reflecting mirror 4g and a sterilizing lamp 4c. Then, the damage of the film 3a is reduced by indirectly sterilizing the film 3a by an ultraviolet ray.