We study the actions of local conformal vector elds X ∈ conf(M, g) on the spinor bundle of (M, g) and on its classical counterpart: the supercotangent bundle M of (M, g). We rst deal with the classical framework and determine the Hamiltonian lift of conf(M, g) to M. We then perform the geometric quantization of the supercotangent bundle of (M, g), which constructs the spinor bundle as the quantum representation space. The Kosmann Lie derivative of spinors is obtained by quantization of the comoment map. The quantum and classical actions of conf(M, g) turn, respectively, the space of di erential operators acting on spinor densities and the space of their symbols into conf(M, g)-modules. They are ltered and admit a common associated graded module. In the conformally at case, the latter helps us determine the conformal invariants of both conf(M, g)-modules, in particular the conformally odd powers of the Dirac operator.Keywords: onform l geometryD symple ti superm nifoldD spin geometryD geometri qu nE tiz tionD onform lly inv ri nt di'erenti l oper torsF