Disclosed is a valve ignition prechamber for an internal combustion engine which includes a combustion chamber in which a main load more or less diluted with a neutral gas is ignited, the prechamber including a lamination cavity into which an ignition unit opens and in which a lamination injector can inject under pressure an easily flammable pilot load, a lamination valve being able to close all or part of the lamination duct, in particular under the effect of the pressure of the gases prevailing in the combustion chamber.