Abstract: The invention relates to a sensor (S), in particular for an electrical network of an electrically driven vehicle, in particular in an electric car. The sensor according to the invention comprises first of all a measuring device (ME) for current measurement and/or for voltage measurement in the electrical network, in particular with a low-resistance current sense resistor for current measurement according to the four-wire technique. Furthermore, the sensor (S) according to the invention comprises an integrated insulation monitoring device (ME, IQ, Rk, S3) for monitoring an electrical insulation of high-side and/or low-side of the electrical network. The sensor (S) according to the invention is characterized by the fact that the insulation monitoring device (ME, IQ, Rk, S3) operates actively and impresses measurement pulses into the electrical network for insulation monitoring.