Degradation of thin film interconnects and ultra‐thin dielectrics is studied within a stochastic approach based on a percolation technique. The thin film is modelled as a two‐dimensional random resistor network at a given temperature and its degradation is characterized by a breaking probability of the single resistor. A recovery of the damage is also allowed so that a steady‐state condition can be achieved. The main features of experiments are reproduced. This approach provides a unified description of degradation and failure processes in terms of physical parameters.