A method for the manufacture of a cathode filament of an X-ray tube and an X-ray tube formed by the method wherein the filament has at least two legs and one body, the filament being a single-piece filament. Spraying at least one material on a support by plasma spraying or by another deposition technique to obtain the filament molded on the support and separating the filament obtained from the support. The filament obtained has a variable thickness and a variable composition. The thicknesses of the legs and of the body as well as the composition of the filament can be modified according to the user's needs.