In conjunction with the German Aerospace Center, dr. wernecke Feuchtemesstechnik GmbH has developed a sensor (DWF-AWB-25) for the investigation of humifity at the Mars surface. Trace moisture and high humidity can be determined in a single measuring instrument which was developed for the research. Two different sensors are covering a wide measuring range for humidity and temperature. According to the ambient conditions a measurement program can be selected. The device has demonstrated its suitability for use during an Antarctic expedition in 2009.