In a system for monitoring settling of a transient response of a load controlled by a following controller, a state estimation unit generates a state estimation quantity which shows an estimated state of the load. A settling evaluation function operation unit generates an evaluated output by inputting, to a predetermined settling evaluation function, the state estimation quantity and a control quantity output to the load by the following controller. A count unit generates time data showing a time elapsed since commencement of supervision of settling. A comparator unit compares the evaluated output and the time data with each other, and replaces the time data of the counter unit with the evaluated output on the basis of a comparison result. A decision making unit generates a settling completion signal when the time data shows a predetermined time.