Thierry JECKO From classical to semiclassical non-trapping behaviour: a new proof. (136K, postscript) ABSTRACT. For the semiclassical Schr\"odinger operator with smooth long-range potential, it is well known that the boundary values of the resolvent at non-trapping energies exist and are bounded by $O(h^{-1})$ ($h$ being the semiclassical parameter). We present here a new proof of this result, which avoids the semiclassical Mourre theory and makes use of semiclassical measures.