Abstract: Process for the preparation of a composite material formed of reinforcing fibers, regularly distributed and oriented in more than two directions, and of a matrix filling up the space between said fibers.According to the invention, said process consists in: producing a convex brush of said reinforcing fibers, regularly distributed and fixed by one of their ends on a convex base, said fibers being subjected to an intensive D.C. electrostatic field, oriented in parallel to said fibers so that the fibers are immobilized in stretched condition perpendicularly to the base surface; inserting between said fibers, layers or grids of fibers, disposed successively at 90.degree. from one another, said insertion being carried out while the reinforcing fibers fixed on said base are subjected to the intensive D.C.