A test device for testing a distance sensor operating with ultrasonic waves, wherein the distance sensor to be tested comprises at least a sensor radiating element for emitting a transmission signal and a sensor receiving element for receiving a reflected signal. For effective and accurate testing and stimulation of the distance sensor, the test device has a test receiving element for receiving ultrasonic waves emitted from the distance sensor to be tested, and at least one test radiating element for radiating test ultrasonic waves, and a signal processing unit, wherein ultrasonic waves received by the test receiving element are transmitted as a received signal to the signal processing unit and the signal processing unit, as a function of the received signal and simulation distance information relating to a distance to be simulated, and determines an excitation signal for the test radiating element.