A membrane for cultivating adherent or suspension cells, in particular adherent cells. The membrane permits adhesion and proliferation of the cells due to the irradiation of the wet or dry membrane with gamma or beta rays or an electron beam in a dose of from 12.5 to 175 kGy in the presence of oxygen. The resulting membrane may be used without any pre-treatment with surface-modifying substances. A method for preparing such an irradiated membrane for cultivating adherent or suspension cells. Methods of using such a membrane for cultivating adherent or suspension cells.