Abstract: The invention relates to a device for handling two liquids which are to be mixed together in a sterile manner directly before administration, to form an infusion solution to be administered parenterally, the apparatus comprising a first container in the form of a flexible bag made of plastics for receiving the one liquid and provided with a hanging member and a stopper closure, and a second container for the second liquid, which is likewise provided with a stopper closure, the two containers being held together and their interior spaces being capable of being put into communication with one another for the sterile mixing of the liquids contained in them. The second container is a rigid flask which can be closed in a vacuum-tight manner and has a volume corresponding to the volume of both liquids.