A method for producing methanol from a synthesis gas containing hydrogen and carbon oxides with a high content of inert components includes passing the synthesis gas through a synthesis reactor so as to catalytically convert a part of the carbon oxides to methanol. The methanol is separated from the obtained mixture from the reactor. The mixture liberated from methanol is separated into a cycle stream and a purge stream. The cycle stream is recirculated so as to form a synthesis circle and combined with a fresh gas stream including hydrogen and carbon oxides before being charged into the synthesis reactor. The purge stream is supplied to a secondary reactor so as to catalytically convert a further part of the hydrogen and carbon oxides to methanol. Further methanol is separated the obtained mixture including synthesis gas, inert components and methanol vapor.