Abstract: An open-end spinning device (1) with a forwardly-opening vacuum-loaded rotor housing (2), a high speed spinning rotor (3) rotating in the rotor housing and with a fiber conduit plate (4) for closing the rotor housing. The fiber conduit plate (4) has a replaceable conduit-plate adapter (10) forming the mouth area of a fiber guide conduit and a yarn withdrawal jet. The conduit plate adapter (10) is detachably fixed in a receptacle (7) of the fiber conduit plate (4) only in a frictionally connected manner by means of a magnetic coupling (15) which can be easily and rapidly detached when necessary yet is reliable and exact during operation and assembly.