Porous glasses are used for the first time as template in a nanocasting approach to synthesize nanoporous silicon carbide. By varying the structural parameters of the glasses, the properties of the resulting silicon carbides can be controlled. Furthermore, the template and the replicate thereof are distinguished by a three-dimensional, continuous pore network. Pore sizes of the SiC DUT-88 (DUT = Dresden University of Technology) are varied in the nanoscale (10-50 nm) and specific surface areas of up to 477 m² g^-1 are reached after precursor-ceramic conversion at 1300 C. Even beads of nanoporous silicon carbide can be synthesized if shaped porous glass templates several hundred microns in diameter are used. The results demonstrate how to control the silicon carbide structures in a very appropriate and extended way. Such nanoporous silicon carbide materials are promising components for application as e.g. filter, membrane or catalyst supports.