[en] We have measured the partial widths for the three reactions e⁺e^-→Z⁰→e⁺e^-, μ⁺μ^-, τ⁺τ^-. The results are Γ_ee=84.3±1.3 MeV, √Γ_eeΓ_μμ=83.3±1.3 MeV, and √Γ_eeΓ_ττ=83.9±1.4 MeV, where the errors are statistical. The systematic errors are estimated to be 1.0 MeV, 0.9 MeV, and 1.4 MeV, respectively. We perform a simultaneous fit to the cross sections for the e⁺e^-→e⁺e^-, μ⁺μ^-, and τ⁺τ^- data, the differential cross section as a function of polar angle for the electron data, and the forward-backward asymmetry for the muon data. We obtain the leptonic partial with Γ_ll=84.0±0.9(stat). MeV. The systematic error is estimated to be 0.8 MeV. Also, we obtain the axial-vector and vector weak coupling constants of charged leptons, g_A=-0.500±0.003 and g_V=-0.064_-0.013^+0.017. (orig.)