An object is to suppress reduction of energy production as much as possible while ensuring an expected lifetime. There is provided a device of adjusting a curtailment strategy for a wind turbine, the device including: a fatigue equivalent load calculation unit that calculates a fatigue equivalent load for evaluating a fatigue damage of the wind turbine in a predetermined time period by using load data of the wind turbine; and a setting value update unit that compares the fatigue equivalent load with a reference load determined by an expected lifetime of the wind turbine, and, when a difference between the fatigue equivalent load and the reference load exceeds a predetermined threshold value, updates the condition setting value for the curtailment that is currently employed according to the difference.