To appropriately perform fuel flow rate control of a main fuel control valve even if charging air containing VOC is supplied to a combustor of a gas turbine.

A fuel control device includes a main fuel supply system 39 provided with a main fuel control valve 33 supplying fuel to the combustor 9 of a regenerative cycle gas turbine, a pilot fuel supply system 41 provided with a pilot fuel control valve 43, and a control means 50. A control means includes data regulating fuel reduction rate when charging air containing VOC is supplied by a relation of load and VOC concentration. Fuel reduction rate is calculated from the data by load and VOC concentration and correction reducing pilot flow rate is performed during supply of charging air containing VOC. Main flow rate is increased by reduction quantity of pilot flow rate and appropriate control by main flow rate is enabled even if total flow rate is reduced.