Abstract: The invention relates to a porous burner with a housing, which has an inlet for a fuel-air mixture and an outlet for the exhaust gas mixture generated in the burner, where in flow-direction of the fuel-air mixture the housing contains an ignition space with an ignition device and adjacent to this space a porous burner medium. On the inlet side the ignition space is provided with a stabilizing element, which reduces the inlet cross-section and directs the flow of the fuel-air mixture essentially perpendicular to the inlet cross-section of the porous medium. The porous burner is provided with a device for controlling the mass flow of the fuel-air mixture, which serves to shift the combustion zone from the ignition space into the porous medium.