AbstractA transmission experiment with 14 MeV neutrons on a beryllium spherical shell of 5 cm thickness is reported. The neutron leakage spectrum in the 1.2–16 MeV range was measured by a proton recoil spectrometer based on the NE-213 scintillator. Comparison with calculations revealed that nuclear data from LASL-SUB and JENDL-3.1 libraries cause overestimation of the neutron leakage spectrum in the energy intervals 1.2–8 MeV and 12.5–16 MeV. Data from ENDF/B-VI and IV libraries overestimate the leakage spectrum in 3–8 MeV and 12.5–16 MeV intervals.