Abstract: A hydraulic drive valve monitoring device includes a determination part and an alarm part. The determination part is configured to determine whether there is a sign of failure in the hydraulic drive valve device based on a result of comparison between a transition of a working fluid pressure measurement value obtained by measuring a pressure of the working fluid flowing into the valve body part and a transition of a working fluid pressure reference value set for the pressure of the working fluid flowing into the valve body part, when the opening degree of the valve body part is changed. The alarm part is configured to output an alarm when the determination part determines that there is a sign of failure in the hydraulic drive valve device.