[en] The electroweak radiative corrections to the partial decay widths of the Z-boson into a pair of leptons or quarks have been calculated in the standard theory: Z→anti ll, anti νν, anti qq. Results are presented in terms of electroweak form factors with simple physical interpretation. As a result of the calculational scheme used, the corrections are at most of the order of some percents. They are rather stable against a variation of the Higgs boson mass Msub(H). In case of a heavy t-quark, the effective mixing paramete k x sinsup(2)THETAsub(W) may deviate from sinsup(2)THETAsub(W)=1-Msub(W)sup(2)/Msub(Z)sup(2) by about 10%