AISI 420 martensitic stainless steel samples and silicon (100) were coated with tantalum nitride doped with copper and silver nanoparticles TaN(Ag-Cu) to improve their hardness and wear resistance. The coatings were deposited by unbalanced DC Magnetron Sputtering technique, using a tantalum target and other silver/copper composite target (50/50%at), confronted each other. The coated samples were subjected to an appropriate heat treatment at 250 °C for 8 minutes to achieve a controlled diffusion of Ag-Cu nanoparticles to the TaN(Ag-Cu) surface. Due to their mechanical and tribological properties depend, not only on the content of Ag-Cu, but also on the size, shape and density of nanoparticles of Ag-Cu on the surface of the coating. The influence of the Ag-Cu content on the microstructure and mechanical and tribological properties of the composite coating were evaluated before and after the heat treatment was evaluated. In general terms, the microhardness and wear rate increased initially with Ag-Cu content, but then dropped down for contents higher to 0.71% at, exhibiting the lubricating effect of Ag-Cu nanoparticles in the compound before and after heat treatment. The heat treated C3 sample showed a microhardness of 15 GPa, very superior to the hardness of AISI 420 stainless steel, as well as a wear rate six orders of magnitude lower than the steel.