The Mini-EUSO telescope, approved by ASI (Italian Space Agency) and Roscosmos (Russian Space Agency) as long-term program of space experiments to be launched on the Progress spacecraft during the Expedition 60/61 in 2019, will be placed on a nadir-facing, UV transparent window on the ISS Russian Zvezda module looking down on Earth. As one of the JEM-EUSO collaboration missions, its first objective is to observe UV light produced by UHECR (Ultra High Energy Cosmic Ray) events from upper atmosphere (~ 400 km altitude), moreover, from this point of view, Mini-EUSO will perform, for the first time, high-resolution mapping of night-earth UV (300 - 400 nm) emission, focusing on terrestrial background sources, TLEs (Transient Luminous Events), bioluminescence, meteoroids burning in atmosphere, search for SQM (Strange Quark Matter) signals, as well as detecting and mapping space debris. The integration of the instrument, currently underway at the University of Rome Tor Vergata, is at an advanced stage in order to be compliant with a launch opportunity in June 2019. The on ground test results will be presented.