Arrangement for automatically measuring the salt concentration in cooking water, comprising: a kettle containing the cooking water, wherein said sensor comprises a toroidal probe that is submerged in the cooking water bath and on an end portion of which there is provided an annular ferromagnetic core, round which there are wound two distinct conductive windings, the respective terminals of which are connected outside; said probe comprises a sensor (11) for the temperature of the cooking water bath. The two windings are connected to a processing and control unit, which is provided with means for detecting and measuring the voltages across said two windings, measuring the ratio of these two voltages to each other, and processing said ratio so as to produce a value that correlates to the electric conductivity of the cooking water bath, wherein the value of the electric conductivity of the cooking water bath is furthermore rectified with the value of the temperature being measured by said temperature sensor.