A round baler includes a bale chamber in which a round bale can be produced, and a wrapping device with which a completely pressed round bale can be wrapped with a first film in the bale chamber, and a feed device for introducing the first film into the bale chamber. The round baler also includes a feed point at which the first film can be fed to the bale chamber, and an ultrasonic sensor which is arranged at the bale chamber. The ultrasonic sensor is arranged at the bale chamber in such a way that with the ultrasonic sensor it is possible to determine whether the film is present on a surface of the round bale.
