A method for obtaining highly pure hydrogen from a raw gas begins with heating and/or treating a semipermeable material made of metal or a metal alloy, preferably, conducting an electric current through the semipermeable material at the beginning of the method in order to increase the quantity of hydrogen passing through the material. A device for obtaining highly pure hydrogen from the raw gas includes a semipermeable material which forms a boundary between the interior of a pressure vessel and the outer region of the pressure vessel and which is permeable to hydrogen. The device is designed such that is can be heatable or treatable at least in sections, in particular, by means of electric energy.