[en] In this paper a procedure is described for the production of fission molybdenum. The production method is particularly suitable for those, which do not dispose on highly enriched uranium. The aim was to realize a simple technology. Starting from irradiated uranium oxide the following steps are included: dissolution of the target in 6 M nitric acid, separation of ⁹⁹Mo from uranium and the bulk of other fission products by adsorption/desorption on alumina and purification of the molybdenum fraction by thermochromatography. The waste treatment is described too. The final product ⁹⁹Mo is well suited for manufacturing high quality ⁹⁹Mo/^99mTc generators. (author)