A neutron has excellent transparency of matter and a nuclear magnetic moment. Owing to these properties, neutron scattering is a powerful method to investigate the structure and dynamics of atoms and electron spins in condensed matter. Since 1961, the Neutron Science Laboratory (NSL) has been playing a central role in neutron scattering activities in Japan not only by performing its own research but also by providing a general user program using the university-owned 12 neutron scattering spectrometers installed at the research reactor JRR-3 (20 MW), JAEA (Tokai, Ibaraki). Furthermore, NSL owns stateof-art inelastic neutron scattering spectrometer HRC in J-PARC, which started its operation in 2009. Major research areas supported by the NSL user program are solid state physics (strongly correlated electron systems, superconductors, heavy fermion systems, topological materials, multiferroic materials, novel quantum phases etc.), soft matter (polymers, gels, membranes etc.), complex systems (glass, liquid, clathrate materials, etc.), material science (ionic conductors, hydrogen systems etc.), biological physics, and neutron optics. The NSL also operates the US-Japan cooperative program on neutron scattering since 1984.