ULTRASONIC SENSOR FOR A MOTOR VEHICLE, DRIVER ASSISTANCE SYSTEM AND MOTOR VEHICLE

The invention relates to an ultrasonic sensor (5) for a motor vehicle (1) having a membrane (10) comprising a membrane bottom (11) and a membrane lateral wall (12), wherein the membrane bottom (10) has a front side (16) facing in an ultrasonic signal transmitting direction (14) of the ultrasonic sensor (5) and a rear side (17) opposite to the front side (16), wherein the ultrasonic sensor (5) has a cleaning device (9) for cleaning the front side (16) of the membrane bottom (11). The invention further relates to a driver assistance system (2) as well as a motor vehicle (1).