An amorphous Ti-Ni alloy film was prepared by RF sputtering on a water-cooled chromium substrate to investigate changes in its corrosion resistance due to annealing, and to study its possibilities of application as a coating material having a high corrosion resistance. Structural analysis of the sample was made by X-ray diffraction and Auger electron spectroscopy (AES), and its corrosion resistance was evaluated by means of an immersion test in HCl solutions. The results obtained are as follows: 1) A Ti-Ni alloy film on a chromium substrate was confirmed by X-ray diffraction analysis to be amorphous. 2) Immersion of the sample in 1 N-HCl before annealing caused the substrate to dissolve. This means that this sample does not provide sufficient protection against corrosion. 3) After annealing at 500°C, volume diffusion of the chromium substrate was not observed under AES depth analysis, but the corrosion resistance and the adhesion of the film increased markedly.