  We calculated the parity nonconserving (PNC) 6s -> 7s amplitude in Cs. In the
Dirac-Coulomb approximation our result is in a good agreement with other
calculations. Breit corrections to the PNC amplitude and to the Stark-induced
amplitude $\beta$ are found to be -0.4% and -1% respectively. The weak charge
of $^{133}$Cs is $Q_W=-72.5 \pm 0.7$ in agreement with the standard model.
