The present invention relates to a process for the manufacture of a three-dimensional nonwoven, a manufacturing line for implementing this process and the resulting three-dimensional nonwoven product. Process characterized in that it consists in using a folding element (5) to apply, to an incoming web containing a proportion of thermoplastic fibers and/or filaments or fixing material, an initial fixing of the fold of the incoming web in the form of peaks and troughs, brought about by blades extending radially on ends of the folding element (5), this initial fixing being applied either by maintaining the folding element (5) itself at a set temperature, or by heating the incoming web. The invention is more particularly applicable to the textile industry, especially the manufacture of nonwovens.