What is described is a method and an installation for the simultaneous production of methanol synthesis gas, ammonia synthesis gas, carbon monoxide and carbon dioxide from natural gas, in which several plant elements (or plant units) are serially arranged one by one in one single production chain, whereat these elements comprise: a first reactor A, in which the natural gas is transformed under oxygen supply into a synthesis gas mixture comprised of carbon monoxide, carbon dioxide, hydrogen and steam (water vapor), a second reactor B, which allows to control the transformation of carbon monoxide into carbon dioxide, optionally a compressor C for compressing the generated gases, an absorber D for the absorption of carbon dioxide and for obtaining the carbon monoxide-hydrogen mixture used for methanol synthesis, a low-temperature separator E, in which ammonia synthesis gas is obtained by introducing liquid nitrogen, and in which simultaneously carbon monoxide, argon and methane are removed.