A gas turbine combustor including a cluster-type burner is adapted to stabilize a combustion state by supplying a desired flow rate of combustion air to inner circumferential and outer circumferential fuel nozzle regions. A burner section of the combustor includes a plurality of fuel nozzles 2 and a premixing plate 4 in which are formed a plurality of premixing passages 3 each positioned at a downstream side of the corresponding one of the fuel nozzles 2, injected fuel from the plurality of fuel nozzles 2 being mixed with air in the premixing passage 3 before being supplied to a combustion chamber and burnt therein. The burner section also includes guide vanes 34, 35, 36 that rectify a flow of air and guide this air flow from an upstream side of the fuel nozzles 2 to fuel injecting ports of the fuel nozzles 2; wherein the guide vanes guide a desired amount of air to the fuel injecting ports of the fuel nozzles and stabilize combustion.