An internal combustion engine having: - at least one cylinder head - an intake manifold - a plurality of piston-cylinder-units in which pistons are movably arranged - a plurality of main combustion chambers - a plurality of intake ports wherein each intake port is connected to one of the main combustion chambers and to the intake manifold - a plurality of prechambers wherein each prechamber is connected to one of the main combustion chambers and is provided with a prechamber gas valve and an ignition device - an electronic control unit configured to provide the prechamber gas valves with a mixture of fuel gas and air wherein each prechamber has at least: - a first sub-chamber which is provided with the prechamber gas valve and with the ignition device - a second sub-chamber which is connected to the main combustion chamber by a plurality of first orifices (O 1) and which is connected to the first sub-chamber ()indirectly by at least one third sub-chamber which is connected to the first sub-chamber by at least one third orifice (O 3), preferably a third plurality of orifices (O 3) and which is connected to the second sub-chamber by at least one second orifice (O 2), preferably a plurality of second orifices (O 2) characterized in that following a fluid passage from the first sub-chamber to the main combustion chamber to which the pre-chamber is connected each sub-chamber (71, 72, 73) has a smaller volume than a next sub-chamber (71, 72). - at least one cylinder head - an intake manifold - a plurality of piston-cylinder-units in which pistons are movably arranged - a plurality of main combustion chambers - a plurality of intake ports wherein each intake port is connected to one of the main combustion chambers and to the intake manifold - a plurality of prechambers wherein each prechamber is connected to one of the main combustion chambers and is provided with a prechamber gas valve and an ignition device - an electronic control unit configured to provide the prechamber gas valves with a mixture of fuel gas and air each prechamber has at least: - a first sub-chamber which is provided with the prechamber gas valve and with the ignition device - a second sub-chamber which is connected to the main combustion chamber by a plurality of first orifices (O 1) and which is connected to the first sub-chamber ()indirectly by at least one third sub-chamber which is connected to the first sub-chamber by at least one third orifice (O 3), preferably a third plurality of orifices (O 3) and which is connected to the second sub-chamber by at least one second orifice (O 2), preferably a plurality of second orifices (O 2) - a first sub-chamber which is provided with the prechamber gas valve and with the ignition device - a second sub-chamber which is connected to the main combustion chamber by a plurality of first orifices (O 1) and which is connected to the first sub-chamber ()indirectly by at least one third sub-chamber which is connected to the first sub-chamber by at least one third orifice (O 3), preferably a third plurality of orifices (O 3) and which is connected to the second sub-chamber by at least one second orifice (O 2), preferably a plurality of second orifices (O 2) characterized in that following a fluid passage from the first sub-chamber to the main combustion chamber to which the pre-chamber is connected each sub-chamber (71, 72, 73) has a smaller volume than a next sub-chamber (71, 72).