An Ag/Cr/AlN sandwich was prepared by deposition of pure silver and chromium on an AlN polycrystalline substrate. As-deposited samples were then annealed between 250 and 650 degrees C to investigate the interface reactions in the Ag/Cr/AlN sandwich. When the annealing temperature was higher than 350 degrees C, interdiffusion at the AlN/Cr and Cr/Ag interfaces was observed. When the annealing temperature exceeded 550 degrees C, Cr atoms diffused outwards to the surface across the Ag layer.