The invention relates to a membrane which can be used for cultivating adherent or suspension cells, in particular adherent cells, wherein said membrane allows for the 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. The invention further relates to a method for preparing said irradiated membrane which can be used for the cultivation of cells, in particular adherent cells, and to methods of using such a membrane for the cultivation of cells, in particular adherent cells.