[en] Data on search of instantaneous muon and electron neutrinos in experiments of beam dump type are presented in the review. Neutrino is formed in decays of particles rusulted from pN interactions. First experiments of the dump beam type have been realized at the CERN/SPS accelerator in 1975 and Serpukhov accelerator by the ITEF-IFVE group in 1977 with proton energies of 26 and 70 GeV, respectively. The results of beam dump experiments of the second generation in 1979 in CERN are considered in detail. These experiments have been intended for measuring the effect of instantaneous neutrino. The conclusion is drawn on the presence of instantaneous muon neutrinos in the above experiments