Abstract: The method and apparatus for measuring the current-voltage characteristic curve of a solar panel uses cost-effective equipment and a minimized need of optical output power. A light pulse is applied to the solar panel and the response of the solar panel to the light pulse is measured by varying the electrical load connected to the output of the solar panel. The measurement is carried out with the help of a short-duration decaying light pulse such that the falling tail of the pulse is used for such a short period that the intensity of the pulse does not have time to change essentially during the measurement.