Abstract: Production of methane from a substrate comprising an organic material, by way of example in a process by means of a culture of anaerobic and preferably thermophile microorganisms, which in a processing chamber (8) is brought into contact with the organic material and in which the generated gas is collected. The substrate is introduced into an ante-chamber (7) for pretreatment which is provided with a heating device (28) with the substrate heated in the ante-chamber to at least the temperature that it is intended to have during the process or preferably to a higher temperature, whereafter it is transported to said processing chamber (8) to be brought into contact with the culture of microorganisms.