Abstract: A fiber-reinforced composite material is produced by a method wherein chemical groups are generated on the surfaces of electrically conductive fibers to be used as reinforcing fibers by electrochemical activation in an electrically conductive bath or liquid, the so-activated fibers are treated with a chemical compound in a solvent containing an element capable of combining with the fibers, especially a metal, the compound is decomposed in the solvent to liberate the element and the element is combined with the activated surfaces of said fibers. The activating current for the electrochemical activation is preferably applied to the fibers without mechanical contact by way of the electrically conductive liquid.