To realize achromatic full-field hard X-ray microscopy with a resolution better than 100 nm, we studied an imaging system consisting of an elliptical mirror and a hyperbolic mirror. The figure accuracies of the elliptical and hyperbolic mirrors required to obtain diffraction-limited resolution were investigated using a wave-optical simulator, and then elliptical and hyperbolic mirrors were precisely fabricated, following the criterion of the figure accuracies. Experiments to form a demagnified image of a one-dimensional slit installed 45 m upstream were conducted using the imaging system at an X-ray energy of 11.5 keV at BL29XUL of SPring-8. The system could form a demagnified image with the best resolution of 78 nm. In addition, the field of view to obtain a resolution better than 200 nm was 4.2 micron.