A combustor comprises a fuel flow path (10) which is a flow path for fuel (G1) and which is capable of emitting the fuel to its own exterior; an air flow path (20) which is a flow path for air (G2) and which is capable of emitting the air to its own exterior; and an exhaust gas flow path (30) which has a combustion region (R) wherein an air-fuel mixture that mixes the fuel and the air is burned and which constitutes an exhaust flow path for burned gas that is produced by combustion; wherein the fuel within the fuel flow path and the air within the air flow path are heated by the heat of the burned gas, and the air-fuel mixture is constituted by mixing the fuel emitted from the fuel flow path and the air emitted from the air flow path in the exhaust gas flow path.