To reduce NOx produced by nonuniform combustion by injecting a fuel in a first direction and a second direction formed at a predetermined angle with respect to the first direction, and supplying air to the outside of an injection hole for the fuel injected from the second direction and further supplying air to the further outside of the foregoing supplied air.

Fuel gas 5 such as natural gas is introduced into a nozzle core 14 from an inlet nozzle 9, and is straightened with a straightening plate 10. Part of the gas is injected from an injection hole 18 as flame holding fuel gas 5A. Part of the straightened fuel gas 5 is injected from an injection hole 19 as main fuel gas 5B. The gases are injected in a predetermined direction (first direction) and in a direction (second direction) larger than 0 degree but smaller than 90 degree with respect to the predetermined direction from the nozzle 9. Mixed and combusted injection air 6 is straightened with an injection air straightening plate 2 and is injected. The injection air 6 is mixed with the fuel gas 5B as primary air, and is further mixed with the combustion air 4 after passage through a combustion air guide vane 17.