  The ALICE Collaboration has measured the inclusive production of muons from
heavy flavour decays at forward rapidity, 2.5 < y < 4, in pp and Pb-Pb
collisions at $\sqrt {s_{NN}}$ = 2.76 TeV. The $p_{\rm T}$-differential
inclusive cross section of muons from heavy flavour decays in pp collisions is
compared to perturbative QCD calculations. The nuclear modification factor is
studied as a function of pt and collision centrality. A weak suppression is
measured in peripheral collisions. In the most central collisions, a
suppression of a factor of about 3-4 is observed in 6 < $p_{\rm T}$ < 10
GeV/$c$. The suppression shows no significant $p_{\rm T}$ dependence.
