With a small double-mirror setup, we used grazing-x-ray interferometry to study nanometric steps. These one-dimensional steps were microfabricated upon the surface of one of the two mirrors; the other mirror provided the reference wave. Two geometries were studied. In the longitudinal case in which the x rays are parallel to the step edges, it is straightforward to determine the step size. In the transverse case, one deals with Fourier holography, and a reconstruction process for a phase object had been demonstrated for the case of a single step.