Abstract: A combustor for a gas turbine engine of a lean premixed combustion type, includes: a fuel jetting device configured to jet a premixed fuel into a combustion chamber so that the premixed fuel burns in a premixed combustion zone which is formed in the combustion chamber; and an additive fuel supply unit disposed downstream of the premixed combustion zone so as to additionally supply fuel into the combustion chamber. The additive fuel supply unit includes first and second additive fuel supply devices disposed in a two-stage arrangement such that the second additive fuel supply device is positioned downstream of the first additive fuel supply device.