Abstract: The present invention relates to a fluid fuel burner with very low emission f nitrogen oxides, comprising, in known manner, means for injecting the fuel into a hearth at least one primary air supply conduit around said injection means, and at least one secondary air supply conduit located radially on the periphery outside the primary air supply conduit. According to the invention, said injection means comprise multiple orifices creating a plurality of independent divergent flames in the hearth, and the burner comprises as many secondary air supply injectors as there are said flames, each of said injectors being placed axially and angularly with respect to one of these flames, in a position such that it furnishes thereto an additional air fluid after a first phase of combustion.