Abstract: A yarn brake has two brake disks, retained with axial play in a support or bearing device, which are retained against one another via resiliently yielding device, such as permanent magnets. The brake disks are rotatably supported in the support or bearing device. Via an oscillatory motion generator, such as an electromagnet, mechanical or other device, the support or bearing means is set into mechanical oscillation that is essentially axial to the brake disks or in other words parallel to the axis of rotation defined by the rotation of the brake disks. The brake disks are carried along only slightly or not at all by the support or bearing device and the oscillatory motion generator.