  The properties of canonical and microcanonical ensembles of a black hole with
thermal radiation and the problem of black hole evaporation in 3-D are studied.
In 3-D Einstein-anti-de Sitter gravity we have two relevant mass scales,
$m_c=1/G$, and $m_p=(\hbar^2\Lambda/G)^{1/3}$, which are particularly relevant
for the evaporation problem. It is argued that in the `weak coupling' regime
$\Lambda<(\hbar G)^{-2}$, the end point of an evaporating black hole formed
with an initial mass $m_0>m_p$, is likely to be a stable remnant in equilibrium
with thermal radiation. The relevance of these results for the information
problem and for the issue of back reaction is discussed. In the `strong
coupling' regime, $\Lambda>(\hbar G)^{-2}$ a full fledged quantum gravity
treatment is required. Since the total energy of thermal states in anti-de
Sitter space with reflective boundary conditions at spatial infinity is bounded
and conserved, the canonical and microcanonical ensembles are well defined. For
a given temperature or energy black hole states are locally stable. In the weak
coupling regime black hole states are more probable then pure radiation states.
