Abstract: The invention concerns a method and a device for non-invasive measurement of a tissue and in particular of the skin bilirubin level. The inventive device is characterized in that it comprises: a reading head (1) capable of sending several flashes of various specific wavelengths towards the tissue (2) to be examined and of receiving and measuring in return the reflected light; a calculator, such as a microprocessor, capable of calculating for each wavelength the amount of reflected light and bring it to a value calculated proportionally to a reference value identical for a predetermined wavelength; and a comparator for comparing the calculated value to a table of reference values.