Polycrystalline materials like metals fail in creep conditions due to development of inter- or intra-granular voids. The model of creep damage is proposed which simulates voids growth on microscale using Cellular Automata (CA) technique at RVE level, coupled with creep deformation on macroscale. It is assumed that experimentally observed creep deformation is a result of interaction between hardening and softening of a material. The softening process is mainly due to voids development and it is built in deformation model by weakening of effective stress by damage parameter calculated by CA part of the model. Parameters of model are based on primary and secondary stages of creep experiments. The results of simulations show that multiscale model predicts quite well times to failure and strains at failure.