A burner which is configured to eject at least one of an oxygen enriched air and a fuel gas from each of a plurality of fluid ejection outlets provided at a tip surface and burns, wherein the plurality of the fluid ejection outlets include a central fluid outlet and peripheral fluid outlet arranged around the central fluid outlet, side walls of a fluid ejection flow path on an upstream side of the central fluid outlet are provided with a pair of openings (42a, 42b) at opposing positions, and the pair of the openings (42a, 42b) communicate with each other via a communication pipe, the fluid ejection flow path on a downstream side of the pair of the openings (42a, 42b) has a sectional fan shape in which a distance between a pair of the side walls gradually expands toward the downstream side, a fluid ejected from the central fluid outlet is oscillated by self-induced oscillation, the peripheral fluid outlet includes a pair of first peripheral fluid outlets arranged to face each other and a pair of second peripheral fluid outlets arranged to face each other, the first peripheral fluid outlets and the second peripheral fluid outlets are arranged around the central fluid outlet so as to sandwich the central fluid outlet, the pair of the second peripheral fluid outlets are arranged in a direction orthogonal to the facing direction of the pair of the openings (42a, 42b), an angle γ° formed by a central axis in an ejection direction of the oxygen enriched air or the fuel gas in the central fluid outlet and the central axis in an ejection direction of the oxygen enriched air or the fuel gas in the pair of the second peripheral fluid outlets satisfies an expression {0° < γ ≤ 15°}, and an outlet width D1 between the pair of the side walls at which the pair of the openings (42a, 42b) are arranged in the central fluid outlet and an outlet width D2 of the pair of the second peripheral fluid outlets in a direction along the outlet width D1 satisfy an expression {0.5D1 ≤ D2 ≤ D1}. wherein the plurality of the fluid ejection outlets include a central fluid outlet and peripheral fluid outlet arranged around the central fluid outlet, side walls of a fluid ejection flow path on an upstream side of the central fluid outlet are provided with a pair of openings (42a, 42b) at opposing positions, and the pair of the openings (42a, 42b) communicate with each other via a communication pipe, the fluid ejection flow path on a downstream side of the pair of the openings (42a, 42b) has a sectional fan shape in which a distance between a pair of the side walls gradually expands toward the downstream side, a fluid ejected from the central fluid outlet is oscillated by self-induced oscillation, the peripheral fluid outlet includes a pair of first peripheral fluid outlets arranged to face each other and a pair of second peripheral fluid outlets arranged to face each other, the first peripheral fluid outlets and the second peripheral fluid outlets are arranged around the central fluid outlet so as to sandwich the central fluid outlet, the pair of the second peripheral fluid outlets are arranged in a direction orthogonal to the facing direction of the pair of the openings (42a, 42b), an angle γ° formed by a central axis in an ejection direction of the oxygen enriched air or the fuel gas in the central fluid outlet and the central axis in an ejection direction of the oxygen enriched air or the fuel gas in the pair of the second peripheral fluid outlets satisfies an expression {0° < γ ≤ 15°}, and an outlet width D1 between the pair of the side walls at which the pair of the openings (42a, 42b) are arranged in the central fluid outlet and an outlet width D2 of the pair of the second peripheral fluid outlets in a direction along the outlet width D1 satisfy an expression {0.5D1 ≤ D2 ≤ D1}.