PURPOSE: To remove directivity of flames, by providing a radiative plate, which has open ports among a number of rising pieces which are arranged to the direction, being intersected by the direction of a blow-off port, to the front part of a burner which has a number of directional blow-off ports.

CONSTITUTION: A radiative plate 14 which has rising pieces 15 and open ports 16 is arranged to the front position of blow-off ports 10 of a burner 9, and flames are jetted out of the open ports 16 of a radiative plate 14. The whole area in a combustion chamber 25 is covered with red-heated flames, with the air being fed into the chamber 25 from the secondary air inlet port 13. Accordingly, materials 23 pierced by a receiving iron skewer can be broiled uniformly by the intermediary of an opening 8.