A method for producing methanol from inert-rich syngas includes installing a catalytic pre-reactor is upstream of the single or mufti-stage synthesis loop, a first part of the syngas being converted to methanol in the catalytic pre-reactor. Furthermore, an inert gas separation stage, for example a pressure swing adsorption system or a membrane system, is connected downstream of the synthesis loop, whereby a hydrogen-enriched syngas stream can be returned to the synthesis loop. In the processing of methane-rich syngas, the inert gas separation stage may also comprise an autothermal reformer in which methane is converted to carbon oxides and hydrogen, which are also returned into the synthesis loop.