The total external reflection of a single-layer mirror is no longer useful for grazing incidence optics in the hard x-ray region (10-100keV), whereas the Bragg reflection of multilayers is more advantageous in this region. Recently, a hard x-ray telescope was tested for practical use in the energy band 24-36 keV by making use of multilayer supermirrors. The focused image was measured by a newly developed position-sensitive CdZnTe solid-state detector. Further development of hard x-ray optical systems is proceeding in orderto extend the energy region up to 100keV and to improve the image resolution. These developments may open upnew research fields in the hard x-ray region.