Fe oxide or ferric hydroxide, obtained from brown Fe ore, minette ore, limonite, and Fe residues from H2O purification or from Fe scale are used. The Fe oxides or hydroxides are mixed with the usual activators and carriers. The finished catalysts are pressed to an apparent d.>0.6. In converting water gas under pressure hydrocarbon yields of 128-147 gm. per m.3 of inert-free synthesis gas are obtained.