A ceramic burner includes a fuel gas supply conduit having a gas delivery region opening into a mouth portion and a mixing and aspiration region communicating with the gas delivery region, and an air supply conduit having nozzles opening into the mixing and aspiration region of the fuel gas supply conduit. The mixing and aspiration region has an angular configuration including a first segment inclined with respect to the axis of a combustion chamber of an air heater within which the burner is positioned and a second segment inclined with respect to the first segment and in communication therewith at a position of directional change. The gas delivery region extends coaxially with respect to the combustion chamber. The nozzles of the air supply conduit include first and second sets of nozzles, the first set of nozzles being directed toward an opposite wall of the first segment of the mixing and aspiration region adjacent the position of directional change, and the second set of nozzles being directed toward the mouth portion. The gas delivery region has extending thereinto, at positions adjacent the mouth portion, a plurality of projections.