Abstract: In order to measure the moisture content in skin, especially in the keratinous layer (stratum corneum), at least two electrodes are employed, at least one of which electrodes is placed on the skin where moisture has to be measured, the electrodes are supplied with a periodic voltage with a frequency of less than 50 kHz, and the susceptance in the keratinous layer is measured beneath the electrode or electrodes. In an apparatus for measuring the moisture content in skin three electrodes are employed, a periodic voltage being applied to two of these. The susceptance is measured below one of the electrodes, uninfluenced by the other electrodes, the measurement thus being truly monopolar.