  Based on the mathematically well defined Pad\'e Theory, a theoretically safe
new procedure for the extraction of the pole mass and width of a resonance is
proposed. In particular, thanks to the Montessus de Ballore theorem we are able
to unfold the Second Riemann Sheet of an amplitude to search for the position
of the resonant pole in the complex plane. The method is systematic and
provides a model-independent treatment of the prediction and the corresponding
errors of the approximation.
