The present invention relates to an X-ray source comprising an electron source (1) for the emission of electrons (E), a target (4) for the emission of characteristic, substantially monochromatic X-rays (C) in response to the incidence of the electrons (E) and an outcoupling means (11) for outcoupling of the X-rays. To achieve characteristic, substantially monochromatic X-rays with a high power loadability electrons are incident on a metal foil (5) of a thickness of less than 10µm and a base arrangement (7, 12) is arranged wherein the metal of said metal foil (5) has a high atomic number allowing the generation of X-rays (C) and the material substantially included in the base arrangement (7, 12) has a low atomic number not allowing the generation of X-rays (C). The outcoupling means are adapted for outcoupling only X-rays (C) on the side of the metal foil (5) on which the electrons (E) are incident and which is opposite to the side of the base arrangement (7, 12) since on this side almost no bremsstrahlung radiation is generated.