The invention relates to a method for the production of a metallic substrate having a biocompatible surface and to the substrate that is produced by means of said method. The method comprises treatment of a metal, i.e., Ti, Ti alloys with Al, V, Ta, Nb, Ni, Fe, Mo or mixtures thereof, Ta, Ta alloys with Fe, Al, Cr, stainless steel, with a melt of calcium nitrate and an additional component which is an oxygen salt of Na, K, Li, Mg and mixtures thereof, said treatment being effected at 180-480 .degree. C. for 0.1 to 12 hours. A substrate is obtained, wherein the overall layer thickness ranges from 10 to below 1600 nm and the fatigue strength of the substrate is in the same fatigue strength range as that of an untreated substrate at equal number of vibrations N.