Abstract: An improvement in the production of a natural gas substitute comprising at least about 80% of methane by volume by multi-stage methanation of a synthesis gas containing hydrogen and oxides of carbon over fixed-bed nickel-containing catalysts under a pressure of about 5 to 100 bars. The starting synthesis gas, preferably produced by oxygen and water gasification of coal, has about 8 to 25% by volume of methane on a dry basis. It is methanated in a first stage at an inlet temperature of about 230.degree.-400.degree. C. and an outlet temperature of about 550.degree. to 750.degree. C. and then in a second stage at about 230.degree. to 500.degree. C. The process is economical with respect to heat consumption and equipment cost.