[en] The hard beta spectrum (Esub(β) > 10 MeV) of the ²⁵²Cf fission products has been investigated. The measurements were performed in an underground laboratory with a spectrometer with detectors from scintillating plastic. Corresponding calibration curves are presented. The dependence of an upper limit of the electron number Nsub(β) on the energy has been obtained. The Nsub(β) values at Esub(β) > 15 MeV have occurred to be as less at 20 times than those obtained earlier, the investigated energy range having been extended to Esub(β) > 20 MeV, where Nsub(β)=2x10^-8 β/fission. Using the results limitations on the yields of some light nuclei in the fission are placed