The sensitivity of an electrostatic transducer determines the range of pulse-echo detection. Maximum sensitivity can be achieved by increasing the bias voltage within certain limits and by using a light membrane. The tension of the membrane was not found to affect the transducer's sensitivity. By using a uniformly grooved backplate the acoustic properties of the transducer can be optimized. The different sensitivity factors of the electrostatic ultrasonic transducer were confirmed with experimental results. High sensitivity can be achieved by using well manufactured backplates with shallow grooves and a small ridge angle.