[en] β-decay of the lightest isotopes of rubidium ⁷⁷Rb, ⁷⁶Rb, ⁷⁵Rb is studied. Rb isotopes are obtained in the BEMS-2 mass-separator. ⁵⁰Cr target (thickness is approximately 2 mg/cm², enrichment approximately 90%) was irradiated by a beam of ³²S ions accelerated in the U-300 cyclotron. Detector unit of the mass-separator includes a Ge(Li) spectrometer (volume is 23 cm³, resolution 4.0 keV for ⁶⁰Co), surface-barrier β-counter and proton detector. Gamma spectrum is obtained for the decay of ⁷⁷Rb and for ⁷⁷Kr daughter nucleus. Energies and relative intensities are presented in a table. The results are in good agreement with data of other papers. Half-life of ⁷⁶Rb β-activity is refined; it is 39.1+-0.6S. Gamma spectrum is presented. A most intensive line 423.5 keV corresponds to the 2⁺ population. Emission of delayed protons predicted in other papers is not found ⁷⁵Rb half-life is refined; it makes 17.6+-1.6 S. Within the errors it is in agreement with data of an other paper. In the range of 60-700 keV only one γ-line with the energy of 178.8+-0.5 keV is distinct