A gas turbine control device to be used in a generating facility including a gas turbine and a generator for generating power when at least rotational power of the gas turbine is transmitted, the gas turbine control device comprising: a first control section for obtaining a first fuel control command for causing generator output to follow a generator output set value decided based on a demand load, wherein the first control section includes a feedback control section (60, 60a, 60c), wherein the feedback control section (60, 60a, 60c) includes a subtraction section for calculating a deviation of the generator output with respect to the generator output set value, a proportional integral calculation provided in a later stage of control than the subtraction section, and a peak suppression section (66, 66a, 66b, 66c) for suppressing a peak in amplitude characteristics of the generator or a utility grid including the generator, wherein the peak suppression section (66, 66a, 66b, 66c) includes a multiplier section, provided between the subtraction section and the proportional integral calculation, for multiplying an input signal by a gain, and a first gain adjustment section for adjusting the gain of the multiplier section according to output of the gas turbine, and wherein the first gain adjustment section sets a gain given at a time of partial load below a rated load to be smaller than a gain given at a time of the rated load. a first control section for obtaining a first fuel control command for causing generator output to follow a generator output set value decided based on a demand load, wherein the first control section includes a feedback control section (60, 60a, 60c), wherein the feedback control section (60, 60a, 60c) includes a subtraction section for calculating a deviation of the generator output with respect to the generator output set value, a proportional integral calculation provided in a later stage of control than the subtraction section, and a peak suppression section (66, 66a, 66b, 66c) for suppressing a peak in amplitude characteristics of the generator or a utility grid including the generator, a subtraction section for calculating a deviation of the generator output with respect to the generator output set value, a proportional integral calculation provided in a later stage of control than the subtraction section, and a peak suppression section (66, 66a, 66b, 66c) for suppressing a peak in amplitude characteristics of the generator or a utility grid including the generator, wherein the peak suppression section (66, 66a, 66b, 66c) includes a multiplier section, provided between the subtraction section and the proportional integral calculation, for multiplying an input signal by a gain, and a first gain adjustment section for adjusting the gain of the multiplier section according to output of the gas turbine, and a multiplier section, provided between the subtraction section and the proportional integral calculation, for multiplying an input signal by a gain, and a first gain adjustment section for adjusting the gain of the multiplier section according to output of the gas turbine, and wherein the first gain adjustment section sets a gain given at a time of partial load below a rated load to be smaller than a gain given at a time of the rated load.