Abstract: A method and apparatus are disclosed for automatically filling and sterilizing capped and spouted flexible fluid containers. Included is a mechanism for advancing at least an individual empty container toward a filling station; a sterilizing device for sterilizing at least a portion of each spout in a sterilizing chamber; and a device for advancing each spouted container through the sterilizing chamber. The sterilizing device includes means for introducing gaseous hydrogen peroxide into the sterilizing chamber and a mechanism for radiating the spouts in the chamber with pre-selected ultraviolet radiation. Also enclosed is a device for filling the empty container with the substance in a sterile environments.