The invention relates to a measurement device, especially an electrochemical sensor, comprising a sensor element located at a measuring point. The sensor element is accommodated in a housing which is connected by interconnecting electrical cables to an evaluation circuit remote from the measuring point. The interconnecting electrical cables are guided inside a protective device at least in the area close to the measuring point. The protective device (66) is connected to the housing (16) in positive and non-positive fit by a fastening device (66) encompassing the housing (16) and the protective device (66) to form a sealing seat (61).