A combustor comprising: a combustion liner having a combustion chamber formed therein; and a fuel injector mounted to an upstream portion of the combustion liner and configured to inject fuel and air into the combustion chamber, the fuel injector including a fuel injection member having a plurality of fuel injection annular portions, and an air guide member having a plurality of annular-plate shaped combustion air annular portions that guide an air for combustion, the fuel injection annular portions and the combustion air annular portions being arranged concentrically and alternately; wherein each of the fuel injection annular portions includes a plurality of fuel injection holes that are open in a radial direction thereof, the air guide member is disposed on upstream side relative to the fuel injection holes, each of the combustion air annular portions includes a plurality of air guide grooves that are open in an axial direction thereof, and are configured to guide the air in the axial direction to the fuel jetted from the fuel injection holes, each of the air guide grooves being disposed at circumferential positions corresponding to respective fuel injection holes, so that the fuel jetted from the fuel injection holes is deflected by the axially flowing air, each of the fuel injection annular portions is formed as a hollow portion, and a hollow space in the fuel injection annular portion forms an annular fuel flow passage that allows the fuel to flow in a circumferential direction thereof, and each of the fuel injection annular portions includes: a first fuel flow passage that is positioned on a combustion chamber side and is communicated with the fuel injection holes; a second fuel flow passage that is positioned on a side opposite to the combustion chamber, and is supplied with the fuel to be jetted from the fuel injection holes; and an injection nozzle configured to jet the fuel in the second fuel flow passage to a wall surface of the first fuel flow passage on the combustion chamber side. a combustion liner having a combustion chamber formed therein; and a fuel injector mounted to an upstream portion of the combustion liner and configured to inject fuel and air into the combustion chamber, the fuel injector including a fuel injection member having a plurality of fuel injection annular portions, and an air guide member having a plurality of annular-plate shaped combustion air annular portions that guide an air for combustion, the fuel injection annular portions and the combustion air annular portions being arranged concentrically and alternately; wherein each of the fuel injection annular portions includes a plurality of fuel injection holes that are open in a radial direction thereof, the air guide member is disposed on upstream side relative to the fuel injection holes, each of the combustion air annular portions includes a plurality of air guide grooves that are open in an axial direction thereof, and are configured to guide the air in the axial direction to the fuel jetted from the fuel injection holes, each of the air guide grooves being disposed at circumferential positions corresponding to respective fuel injection holes, so that the fuel jetted from the fuel injection holes is deflected by the axially flowing air, each of the fuel injection annular portions is formed as a hollow portion, and a hollow space in the fuel injection annular portion forms an annular fuel flow passage that allows the fuel to flow in a circumferential direction thereof, and each of the fuel injection annular portions includes: a first fuel flow passage that is positioned on a combustion chamber side and is communicated with the fuel injection holes; a second fuel flow passage that is positioned on a side opposite to the combustion chamber, and is supplied with the fuel to be jetted from the fuel injection holes; and an injection nozzle configured to jet the fuel in the second fuel flow passage to a wall surface of the first fuel flow passage on the combustion chamber side.