The influence of annealing on the surface magnetism of a 10 ML film of Fe grown at 120 K on Ag(100) has been investigated with topmost layer sensitivity by spin polarized metastable deexcitation spectroscopy (SPMDS). Silver starts to diffuse to the surface at a temperature of 300 K. The surface magnetization goes through a maximum at T = 300 K and then decreases to zero at higher temperatures indicating that the improvement of the structural order dominates up to room temperature and then is overcome by the presence of silver on the surface that screens the electronic states of iron.