  A measurement is presented of the $t\bar{t}$ inclusive production
cross-section in $pp$ collisions at a center-of-mass energy of $\sqrt{s}=8$ TeV
using data collected by the ATLAS detector at the CERN Large Hadron Collider.
The measurement was performed in the lepton+jets final state using a data set
corresponding to an integrated luminosity of 20.3 fb$^{-1}$. The cross-section
was obtained using a likelihood discriminant fit and $b$-jet identification was
used to improve the signal-to-background ratio. The inclusive $t\bar{t}$
production cross-section was measured to be $260\pm 1{\textrm{(stat.)}}
^{+22}_{-23} {\textrm{(syst.)}}\pm 8{\textrm{(lumi.)}}\pm 4{\mathrm{(beam)}}$
pb assuming a top-quark mass of 172.5 GeV, in good agreement with the
theoretical prediction of $253^{+13}_{-15}$ pb. The $t\bar{t}\to
(e,\mu)+{\mathrm{jets}}$ production cross-section in the fiducial region
determined by the detector acceptance is also reported.
