At present, the interest in investigations of neutron β-decay has increased greatly. The recent growth in experimental results has been brought about by two circumstances: the practical improvement of ultracold neutron storage methods in material and magnetic traps, and the achievement of a level of accuracy for the neutron lifetime and β-decay asymmetry measurements which provides a really interesting check of the weak interaction Standard Model. Figure 1 shows the number of neutron lifetime experiments carried out in various years. The most precise latest experiments are presented in the Table. The average neutron lifetime obtained from these data is 887.0 ± 1.6 s, and the value of the neutron β-decay asymmetry coefficient A is equal to −0.1126 ± 0.0011. The neutron lifetime measurements and β-decay asymmetry measurements carried out at the PNPI, given in the table, are among the most precise world data (8, 13).