PURPOSE: To simplify nitrogen feeding equipment and to feed nitrogen to a combustor without reducing the thermal efficiency of the combustor.

CONSTITUTION: In power generating equipment with coal gasifying gas turbine formed in such a manner that power generating equipment with coal gasifying gas turbine comprises an air separating device 108 to separate oxygen and nitrogen in air from each other; and a boosting means 110 to boost nitrogen, separated by the air separating device, and oxygen separated by the air separating device 108 is fed to a coal gasifying furnace 114 and the boosted nitrogen is fed to a gas turbine combustor 103, the nitrogen is boosted by using an axial flow type compressor and the nitrogen in a boosting state is fed directly to the gas turbine combustor without cooling the nitrogen.