Apparatus for administrating toxic fluid

Device for administrating a toxic fluid, comprising an infusion device for connection to an infusion bag. The infusion device is provided with an insertion portion for connecting the bag, and an infusion chamber for dosing a fluid flow via a flow duct in the insertion portion from the bag to an outlet arranged on the chamber. The insertion portion also comprises a ventilating duct which extends between the bag and the outside of the infusion device and ends in a connection arranged on the side of the infusion device for supplying fluid to be administrated. The connection is provided with at least one membrane which is air tight and penetrable by an injection needle.