In the field of resolution test charts for analysis of the resolution of X-ray tomography systems, a test chart comprises a substrate bearing X-ray absorbent zones, with widths and spacings to allow measurement of the system resolution. To avoid shadow effects when the X-ray illumination beam is divergent and when the absorbent zones have a large height/width ratio (from 2 to 5 for example), the absorbent zones in the diverse points of the pattern have a shape of which a general direction of elevation with respect to the surface of the substrate is rotated toward a point of convergence which is the same for all absorbent zones. The X-ray source is placed at the convergence point, eliminating shadow effects. The oblique elevation can be obtained by specific etching steps, or curvature of the substrate after fabrication of the absorbent patterns, or else by use of two superimposed partial test charts.