An internal combustion burner including a combustion chamber supplied with fuel and with oxidant and at least two combustion devices supplied with oxidant and with fuel. Combining two combustion devices of distinct configurations, which respectively generate two distinct types of flames with a system for cooling the walls of the burner by introducing air along the walls, makes it possible to obtain a burner that supplies a combustion gas temperature of up to 1700° C., while at the same time being easily cooled and occupying very little space so that it can, for example, be housed in an existing installation used in the manufacture of rock wool or glass wool.