In this paper we discuss meromorphic continuation of the resolvent and
bounds on the number of resonances for \emph{scattering manifolds}, a class
of manifolds generalizing Euclidian $n$-space. Subject to the basic
assumption of analyticity near infinity, we show that resolvent of the
Laplacian has a meromorphic continuation to a conic neighborhood of the
continuous spectrum. This involves a geometric interpretation of the
complex scaling method in terms of deformations in the Grauert tube of the
manifold. We then show that the number of resonances (poles of the
meromorphic continuation of the resolvent) in a conic neighborhood of
$\mathbb{R}_+$ of absolute value less than $r^2$ is $\mathcal{O}(r^n)$.
Under the stronger assumption of global analyticity and hyperbolicity of
the geodesic flow, we prove a finer, Weyl-type upper bound for the counting
function for resonances in small neighborhoods of the real axis. This
estimate has an exponent which involves the dimension of the trapped set of
the geodesic flow.