We may now celebrate the 40th anniversary of the discovery of neutrino. The understanding of weak forces acting in Nature was alwaye directly connected·with the investigation of this tiniest and simplest piece of matter. The four decades of neutrino research form a brilliant success story. Pauli told at the beginning of neutrino science that neutrinos would never be detected. But Fred Reines and Clyde Cowan taught us the way of experimenting with neutrinos. To-day sophisticated neutrino eyes are watching at the glowing of different sources in several laboratories.