A control device is connected to a servo mechanism that drives a controlled object and outputs a manipulated variable to the servo mechanism so that a controlled variable tracks a target trajectory. The control device includes a controller and a sensor. The controller acquires a measured value from the sensor and performs model predictive control for each control period using a dynamics model representing a relationship between the manipulated variable and the position of the controlled object to generate the manipulated variable to be output to the servo mechanism. The sensor measures the position of the controlled object. The controller performs model predictive control in a first mode using the measured value when the controlled object has a position within the range, and performs model predictive control in a second mode using an output value of the dynamics model when the controlled object has a position outside the range.