Abstract: A carrier for the cultivation of animal and/or human cells in a fermenter, comprises a polymer base body of a solid formed into a pressure-resistant matrix, with a capillary system for carrying the liquid cell culture medium therethrough, with no cell growth occurring therein, and with interstices for three-dimensional cell growth therein, growth factors for the cells being covalently bonded to the boundary surfaces of the interstices. The carrier can provide a high level of cell density of the order of magnitude of 10.sup.9 cells/ml, by three-dimensional cell growth.