Abstract: An open-end spinning device having a spinning rotor housed within a rotor housing which includes a yarn conduit plate for closing the front side of the rotor housing and a conduit plate adapter, defining a mouth area of a yarn conduit guide and including a yarn draw-off jet, which is removeably arranged in a receptacle of the yarn conduit plate and is easily and quickly replaced in connection with the replacement of a rotor, while providing a reliable and tight fastening of the conduit plate adapter in the open-end spinning device. The conduit plate adapter comprises an extension including fixing elements which can be secured by a fixing arrangement which is movably arranged for selectively abutting the fixing elements for fixing the conduit plate adapter within the receptacle of the yarn conduit plate.