A control system for a plant includes a sensor for detecting an output from the plant, an adaptive controller for controlling a manipulated variable applied to control of the plant in a manner such that an output from the sensor becomes equal to a desired value, and an adaptive parameter-adjusting device for adjusting adaptive parameters used by the adaptive controller. The adaptive controller is configured in a manner adapted to a predetermined dead time shorter than an actual dead time which the plant and the detection means possess. Sampling timing of an input vector input to the adaptive parameter-adjusting device corresponds to the actual dead time.