  $K^{+}\rightarrow\pi^{+}\nu\overline{\nu}$ is one of the theoretically
cleanest meson decay where to look for indirect effects of new physics
complementary to LHC searches. The NA62 experiment at CERN SPS is designed to
measure the branching ratio of this decay with 10\% precision. NA62 took data
in pilot runs in 2014 and 2015 reaching the final designed beam intensity. The
quality of 2015 data acquired, in view of the final measurement, will be
presented.
