Abstract: A thin metallic ferromagnetic alloy ribbon is annealed by continuously transporting it through an oven in order to induce specific magnetic characteristics and in order to remove a production-inherent longitudinal curvature of the ribbon. While the heat-treatment occurs, the ribbon is guided by a channel in a substantially straight annealing fixture. The channel is characterized by slight curvatures along portions of its length, in particular where the ribbon enters into the annealing oven. The curved channel provides an improved thermal contact between the ribbon and the heat reservoir. As a consequence the process can be conducted at particularly high annealing speeds without degrading the desired characteristics.