An apparatus for measuring a filling level of a urea container by determining distance using sound waves (ultrasound) emitted by a sensor and echoes thereof, includes a urea container bottom and a sump with an overall height. The sump is adjacent the urea container bottom and located below the level of the urea container bottom. The sump is connected in an open manner to the urea container and bounded at the bottom by a sump bottom. The sensor is accommodated in the vicinity of the sump and, with a sound-emitting surface for emitting sound waves and receiving echoes of the sound waves, is fitted in the urea container with the sound-emitting surface of the sensor at most adjacent the level of the urea container bottom. A motor vehicle having the urea container is also provided.