A device for monitoring a milk tank. The device is provided with a monitoring unit comprising a computer and a memory for at least temporarily storing data, a thermometer for measuring the temperature of a fluid present in the milk tank, and for supplying to the monitoring unit a temperature signal that is indicative of the measured temperature, and with a meter for measuring an electrical parameter, such as the conductivity, of the fluid present in the milk tank and for supplying to the monitoring unit a parameter signal that is indicative of the measured electrical parameter.