  Measurements of fiducial integrated and differential cross sections for
inclusive $W^+$, $W^-$ and $Z$ boson production are reported. They are based on
$25.0 \pm 0.5$ pb$^{-1}$ of $pp$ collision data at $\sqrt{s} = 5.02$ TeV
collected with the ATLAS detector at the CERN Large Hadron Collider. Electron
and muon decay channels are analysed, and the combined $W^+$, $W^-$ and $Z$
integrated cross sections are found to be $\sigma_{W^+}$ = 2266 $\pm$ 9 (stat)
$\pm$ 29 (syst) $\pm$ 43 (lumi) pb, $\sigma_{W^-}$ = 1401 $\pm$ 7 (stat) $\pm$
18 (syst) $\pm$ 27 (lumi) pb, and $\sigma_Z$ = 374.5 $\pm$ 3.4 (stat) $\pm$ 3.6
(syst) $\pm$ 7.0 (lumi) pb, in good agreement with
next-to-next-to-leading-order QCD cross-section calculations. These
measurements serve as references for Pb+Pb interactions at the LHC at this
nucleon--nucleon centre-of-mass energy.
