COMBUSTION DEVICE

PROBLEM TO BE SOLVED: To provide a combustion device which is adapted to suppress the generation of NOx in a wide range by so altering the flow of combustion secondary air that the combustion secondary air at the time of low combustion does not flow directly to a primary burner port and reducing the quantity of the secondary air flowing into a primary combustion chamber. SOLUTION: The combustion device B comprises a box-like unit 9 covering a burner body 1 having a primary burner port 6 or the port 6 of the body at the upper part and a primary combustion chamber 11 in the interior, and a rectangular secondary burner port part 12 provided at the upper part of the unit 9. Further, the device B comprises a secondary air supply unit 14 provided, in place, at the unit 9 disposed lower than the port 6, and flowing direction altering members 15 so provided as to alter the flow of the combustion secondary air from the unit 14 in the direction separating from the port 6 and to be opposed to the outside from the port 6, wherein the width P of the part 12 is made smaller than the interval Q of the members 15.