We calculate the local density of states for a thin metallic film depo
sited on a superconducting substrate. We use a tight-binding model wit
h a BCS interaction in the substrate. We show that for energies lower
than the superconducting gap of the substrate, the local density of st
ates in the normal metal film presents a structure due to the proximit
y effect. In very thin normal films, we obtain a structure that was mi
ssed in previous calculations. We interpret recent experiments in Au-N
bSe2 systems in terms of this structure.