A combustor includes a combustion tube which has a tubular shape around an axis; a secondary fuel nozzle which is able to inject a secondary fuel in a radially inner direction with respect to the axis, inside the combustion tube; a fuel manifold which is disposed external to the combustion tube, and defines a fuel space which is able to temporarily store the secondary fuel; and a support which supports the fuel manifold with a gap extending radially from the combustion tube. The support has a support plate which is separated from the combustion tube by the gap and spreads in a circumferential direction with respect to the axis, and a support leg which is attached to the combustion tube and supports the support plate to define the gap between the support plate and the combustion tube.