In this study, we evaluate the hardness and morphology of Al layers, which are constructed using Al / Si and alumina / Al / Si. The depth of the hollow in the Al sample, which has native oxide, was measured as 0.5 μm using a Be-Cu probe under the applied force of 10 mN. The relationship between the applied force and the displacement can be explained by the Hertzian theory. In the case of alumina (20 nm, 50 nm) / Al / Si, the hollows were smaller than those predicted by the Hertzian theory. Cross-sectional observations revealed that the Al layer under alumina was deformed vertically and laterally. It was concluded that the breaking of alumina was induced by the deformation of Al.