A method for the manufacture of a carbon nanomembrane is disclosed. The method comprises preparing a metallised polymer substrate and applying on the metallised polymer substrate a monolayer prepared from an aromatic molecule. The aromatic molecule is cross-linked to form a carbon nanomembrane. The carbon nanomembrane is coated by a protective layer and subsequently the carbon nanomembrane and the protective layer are released from the metallised polymer substrate. Finally, the carbon nanomembrane and the protective layer are optionally placed on a support. The protective layer can be optionally removed. The carbon nanomembrane can be used for filtration.