The invention relates to a method of manufacture of an intravascular functional element that can be introduced into a hollow organ and that comprises at least one wire (10) of an alloy having nickel and titanium as alloying elements, with the following steps: preparation of a metal body of the wire (10) with a metallic surface, then formation of a first oxide layer on the metallic surface of the metal body, then performance of a heat treatment of the wire (10) in a nitrogen-containing salt bath for thermal formation of a second mixed oxide layer on the first oxide layer, wherein the total layer thickness is 15 nm to 100 nm and the mixed oxide layer contains TiO2 and at least one nitride, especially titanium oxynitride and/or titanium nitride.