A sterilization unit comprises at least one nozzle pipe for injection of a sterilization agent into a packaging container to be sterilized. The sterilization unit is driven to move in an axial direction, in a downward stroke and an upward stroke, corresponding to a longitudinal direction of the nozzle pipe such that it is inserted into an open end of the packaging container during sterilization thereof. The nozzle pipe is suspended such as to be displaceable in relation to the sterilization unit, in the axial direction.
