The Fe49Cr15.3Mo15Y2C15B3.4N0.3 (numbers indicate at.%) amorphous alloy in concentrated HCl solution was found to have a corrosion resistance of at least one order of magnitude higher than the N-free Fe-base amorphous alloy. X-ray photoelectron spectroscopy analyses were performed to understand the corrosion mechanism. It was found that the enrichment of Cr oxide and the presence of MoN nitrides on the surface in the passive layer were at the origin of the high corrosion resistance of the N-containing Fe-base amorphous alloy.