Abstract. An analogue of the Riemannian Geometry for an ultrametric Cantor set .C; d / is described using the tools of Noncommutative Geometry. Associated with .C; d / is a weighted rooted tree, its Michon tree [29]. This tree allows to define a family of spectral triples .C Lip .C /; H ; D/ using the`2-space of its vertices, giving the Cantor set the structure of a noncommutative Riemannian manifold. Here C Lip .C / denotes the space of Lipschitz continuous functions on .C; d /. The family of spectral triples is indexed by the space of choice functions, which is shown to be the analogue of the sphere bundle of a Riemannian manifold. The Connes metric coming from the family of these spectral triples allows to recover the metric on C . The corresponding -function is shown to have abscissa of convergence, s 0 , equal to the upper box dimension of .C; d /. Taking the residue at this singularity leads to the definition of a canonical probability measure on C , which in certain cases coincides with the Hausdorff measure at dimension s 0 . This measure in turn induces a measure on the space of choices. Given a choice, the commutator of D with a Lipschitz continuous function can be interpreted as a directional derivative. By integrating over all choices, this leads to the definition of an analogue of the Laplace-Beltrami operator. This operator has compact resolvent and generates a Markov semigroup which plays the role of a Brownian motion on C . This construction is applied to the simplest case, the triadic Cantor set, where: (i) the spectrum and the eigenfunctions of the Laplace-Beltrami operator are computed, (ii) the Weyl asymptotic formula is shown to hold with the dimension s 0 , (iii) the corresponding Markov process is shown to have an anomalous diffusion with E.d.X t ; X t Cıt / 2 / ' ıt ln .1=ıt/ as ıt # 0.