Micro-Rain-Radar (MRR) is a unique meteorological radar profiler for hydrometeors in height ranges of 35 m up to 6000 m. It operates at a frequency of 24 GHz. The high resolution in time and height enables the MRR to monitor the genesis of frozen hydrometeors, the melting zone (bright band) and the formation of rain drops. The instrument measures profiles of Doppler spectra and derives drop size distributions, rain rates, liquid water contents, radar reflectivity factors, Doppler velocities, path integrated attenuation. Typical applications include the unattended long term measurement of rain, real time calibration of weather radar and monitoring of melting zone. The MRR has been adapted even for monitoring of avalanches and volcanos.