A performance evaluation apparatus and performance evaluation method capable of efficiently evaluating the performance of a wearable motion assistance device is provided, which assists motions of a wearer's lower back part. In a state where the wearable motion assistance device is secured and mounted on both femur links and a trunk link, torque acting on an axis line of a pitch direction relative to the trunk link for each hip joint is detected while controlling driving forces by first and second driving sources so that a posture of the trunk link and rotation angles of each hip joint and each knee joint virtually match motions of the lower back part of the wearer; and performance of an assist force by the wearable motion assistance device is evaluated based on a detection result of the torque according to drive control of the first and second driving sources.