Ammonia is produced from a synthesis gas comprising nitrogen and hydrogen on a particulate catalyst in at least one reactor at pressures in the range of from 50 to 300 bar and temperatures in the range of 100 to 600 DEG C. A product mixture containing NH3 vapour is withdrawn from the reactor and cooled, thus condensing and separating out the ammonia. A circulation gas is thus produced, which is mixed with fresh synthesis gas and then returned to the reactor as synthesis gas. Unreacted synthesis gas is fed through a first catalytic bed with no cooling tubes and then, as part-reacted synthesis gas, with a NH3 content of 5 to 20 vol. %, through a heat exchanger as the heating fluid. Part-reacted synthesis gas is fed through at least one further catalyst bed, with cooling tubes running therethrough. Unreacted synthesis gas is fed through the cooling tubes of the further catalytic bed as cooling gas and cooling gas, heated to 300 to 500 DEG C, is fed to the first catalytic bed. The cooling tubes and the further catalytic bed flow co-currently.