Method for starting an internal combustion engine which is operated with combustion gas and has internal combustion, in particular a large gas engine, wherein a combustible gas-air mixture is formed in the inlet system, in particular in a gas mixer upstream of a supercharger, wherein during the starting phase compressed air is injected at least temporarily into the cylinder spaces of at least one group (A; B) of cylinders (1, 4, 5; 2, 3, 6) with prechambers, characterised in that the following steps are carried out: - preheating prechambers of at least one first group of cylinders (2, 3, 6) to a defined preheating temperature; - injecting compressed air into all cylinders (1, 2, 3, 4, 5, 6) of the first and second group (A, B) of cylinders (1, 2, 3, 4, 5, 6) at the start of the starting process as long as the rotational speed of the internal combustion engine falls below a defined breakaway rotational speed; - deactivation of the compressed air supply to the first group of cylinders (2, 3, 6) when the breakaway speed is exceeded; - introducing self-igniting pilot fuel into the prechambers of the first group of cylinders (2, 3, 6) when the breakaway speed is reached and igniting the gas-air mixture in the cylinder spaces of those cylinders (2, 3, 6) by means of the self-igniting pilot fuel, wherein first only the first group of cylinders (2, 3, 6) is operated in a fired manner, while compressed air is further blown into the second group of cylinders (1, 4, 5); - introducing self-igniting pilot fuel also into the prechambers of the second group of cylinders (1, 4, 5) and igniting the gas-air mixture in the cylinder spaces of these cylinders (1, 4, 5) by means of the self-igniting pilot fuel when a defined starting speed (n 2) is reached, wherein the compressed air supply to the second group of cylinders (1, 4, 5) is stopped after ignition of the injected gas-air mixture in the cylinder spaces. - preheating prechambers of at least one first group of cylinders (2, 3, 6) to a defined preheating temperature; - injecting compressed air into all cylinders (1, 2, 3, 4, 5, 6) of the first and second group (A, B) of cylinders (1, 2, 3, 4, 5, 6) at the start of the starting process as long as the rotational speed of the internal combustion engine falls below a defined breakaway rotational speed; - deactivation of the compressed air supply to the first group of cylinders (2, 3, 6) when the breakaway speed is exceeded; - introducing self-igniting pilot fuel into the prechambers of the first group of cylinders (2, 3, 6) when the breakaway speed is reached and igniting the gas-air mixture in the cylinder spaces of those cylinders (2, 3, 6) by means of the self-igniting pilot fuel, wherein first only the first group of cylinders (2, 3, 6) is operated in a fired manner, while compressed air is further blown into the second group of cylinders (1, 4, 5); - introducing self-igniting pilot fuel also into the prechambers of the second group of cylinders (1, 4, 5) and igniting the gas-air mixture in the cylinder spaces of these cylinders (1, 4, 5) by means of the self-igniting pilot fuel when a defined starting speed (n 2) is reached, wherein the compressed air supply to the second group of cylinders (1, 4, 5) is stopped after ignition of the injected gas-air mixture in the cylinder spaces.