Abstract: This invention aims to suppress the occurrence of smoke, for example, during a light load operation of a gas turbine, by adopting an air blast method for a pilot nozzle in a dual fuel combustion low NOx combustor. A gas turbine combustor of the present invention is that in a gas turbine furnished with a dual fuel combustion low NOx combustor having a pilot nozzle capable of injecting a gaseous fuel and a liquid fuel simultaneously or selectively, and a plurality of main nozzles disposed around the pilot nozzle and being capable of injecting a gaseous fuel and a liquid fuel simultaneously or selectively, wherein the pilot nozzle has a gas nozzle portion for injecting the gaseous fuel, and a liquid nozzle portion for injecting the liquid fuel, adopts an air blast method for the liquid nozzle portion, uses combustion air as air for an air blast, and throws the combustion air at a liquid film formed in the liquid nozzle portion to atomize the liquid fuel by use of a velocity difference.