This paper aims at the formulation of a computational model for the simulation of adhesion phenomena in micro-electro-mechanical systems (MEMS) under various environmental conditions. The present approach is based on finite-element (FE) simulations of a representative part of the surface. The micro-scale analyses include the contact behaviour of the asperities and different “proximity interactions” like Van der Waals and capillary forces. The model is first validated in the simple case of a sphere over a flat surface and then applied to a realistic surface sample.