Abstract: A method for efficient operation of a heavy oil-burning gas turbine which uses a fuel that has various high-melting point compounds added as corrosion inhibitors with a view to preventing the occurrence of corrosion at elevated temperatures. The amount of addition of the corrosion inhibitor in the initial period of turbine operation is such that the weight ratio of the effective metallic component (M) of the inhibitor to the corrosive component (V) of the fuel is set to lie within the range of M/V=2-5 and thereafter the addition of the inhibitor is reduced in either a stepwise or graded manner over a predetermined cycle of operation within one to six weeks until the amount of the inhibitor added at the end point is one to three tenths of the initial addition.