[en] Propagation of charged particles generated in the solar flare of August 7, 1972 is considered. The experimental data are obtained on ''Prognoz'' and ''Prognoz-2'' stations. The protons were detected in six energy channels from 1 MeV to more than 100 MeV. Alpha particles were detected in two channels with the energy Esub(α) 0.1-0.5 MeV per nucleon and 1-5 MeV per nucleon. The approximation of the time dependence of the proton intensity with the energy Esub(p) >= 15 MeV is performed on the basis of the generalized diffusion equation. It is demonstrated that the propagation of protons is described satisfactorily by the diffusion of particles in the interplanetary space with the diffusion coefficient K(r) approximately rsup(0.8)Rsup(0.17), where R is the particle multiplicity. The proton spectrum from 15 to 720 MV is constructed. The exponential nature of the spectrum makes it possible to assume that particle acceleration is determined by electric fields