Search for K+→π+νν‾ at NA62

Among the meson decays, K→πνν‾ are the cleanest environment, from the theoretical point of view, where to search for new physics effects. The NA62 Experiment at CERN SPS aims to measure the BR(K+→π+νν‾) with a 10% precision by the end of 2018. It has been commissioned with technical runs in 2014 and 2015, and some preliminary results of the detector performances and quality of data are here reported.