PURPOSE: TO improve operational feeling of a gas turbine, by holding response quality of a gas generartor turbine speed for depression of accelerator pedal in an equal state to a case of low idle operation, even if set to high idle operation from a load condition and the like.

CONSTITUTION: Engine body temperature TB is detected by a temperature detector 51 and compared with a refernce value TBR in a comparator 53. While an engine load amount LD is detected by a load detector 55 and compared with a reference value LDR in a comparator 57. Larger one of the correction signals ΔNG1× and ΔNG2× is adopted as a correction value ΔNG0× in a selector circuit 59, and this value is fed to a coefficient unit 61. While a correction amount ΔNG× aplied with weight from a speed setter 13, is input to a function generator 60, and a weight coefficient CNG by the speed for the correction value ΔNG0× is obtained, then this weight coefficient is fed to a coefficient unit 61. The correction value ΔNC× is obtained by the coefficient unit 61, and added to a speed setting value NG× by an adder 62.