Abstract: Disclosed is a process for manufacturing a part, named composite part, formed from at least one composite material including at least one layer of a reinforcing structure impregnated with a polymer matrix within which the reinforcing structure extends, wherein: a composite blank of the composite part is prepared; and a step of curing the polymer matrix of the composite blank is carried out, exerting a pressure on at least one pressed face of the composite blank. The pressure is exerted in the form of a pressure gradient applied to the pressed face of the composite blank so as to cause the gas present within the composite part to flow from a zone of maximum pressurization to a gas evacuation zone. Also disclosed is a device for manufacturing such a part.