The Jiangmen Underground Neutrino Observatory (JUNO) is a neu- trino reactor experiment at kt scale which will address the mass hierar- chy problem. The detector consists of a 20 kt Liquid Scintillator target and will be based in an deep underground laboratory (700 m) located at 53 km distance from the Yangjiang and Taishan nuclear power plant site in China. This specific location will resolve the mass hierarchy by analysing the neutrino oscillation spectra but required severe constraints on the energy resolution at 3% level for 1 MeV. The detector will be equipped with a multi-veto system allowing to detect cosmic muons and for e cient background reduction.
In addition, the experiment o↵ers a rich physics program and will mea- sure the neutrino oscillation parameters at the percent level opening the precision era in the neutrino sector. The detector is currently in the R&D phase and foreseen to start by 2020 horizon.