Abstract: The invention relates to a process for the manufacture of composite products made of thermosetting plastic comprising a first pressure chamber (8) and a second pressure chamber (10). Each of the pressure chambers is provided with an elastically deformable chamber wall (12, 14), a mould configuration comprising at least one tool (16) with a mould chamber capable of accommodating a prepreg material (18). The pressure chambers are oriented with the elastically deformable chamber walls(12, 14) opposing one another, so that, when the press is operated with the mould configuration (16, 18) situated between the elastically deformable chamber walls (12, 14), the latter are at least partially in contact with one another with a pressing force (F) in a moulding stage.