Most of the studies dealing with contact mechanics are focused on the pressure and the deformation at the surfaces of the contacting bodies. However, the stress and deformation in the material underneath the actual surface are also important to study. In this work, the elastic deformations arising in a silicon block that is compressed by a steel ball is studied. More precisely, an optical metrology technique is employed to obtain the deformation in the substrate at a fixed depth. A finite element based model, is also developed in order to numerically estimate the elastic deformation of the silicon block. Moreover, the deformation and corresponding stress fields are also analysed with closed form analytical solutions. Comparisons of the results obtained from the experiments, the numerical simulations and analytical solution show that a good prediction of the deformation can be obtained by the finite element model.