Abstract: To provide a characteristic evaluation device that can properly evaluate a characteristic of a shaft coupling while considering a delay in a response of a motor, a characteristic evaluation device of a shaft coupling includes: a motor system including a drive motor, a rotation angle sensor configured to acquire a rotation angle of a drive shaft, and a motor control unit configured to control the drive motor based on a torque command; a rotational load connected to a driven shaft; and a processor configured to output the torque command and calculate a frequency response of a gain of an amplitude of an angular velocity ? of the rotation angle, wherein the processor is configured to calculate a characteristic of the shaft coupling based on a response characteristic of the motor system and the frequency response.