A low-loss sub-millimeter-wave/THz integrated dielectric waveguide is presented. The proposed waveguide consists of a highly resistive Silicon (Si) guiding channel bonded to a glass substrate. To reduce the waveguide insertion loss due to the glass substrate, part of the substrate below the Si guiding channel is etched. A periodic configuration of supporting beams is used to hold the Si guiding channel over the glass substrate. A low-cost and high-precision fabrication process, which is fully compatible with current Si-based fabrication technologies, is developed for the proposed waveguide. Numerical simulations and experiments are conducted to investigate the performance of the proposed waveguide. Measured attenuation constant of the proposed waveguide is 0.0346 dB/ (average value) over the 440-500 GHz band.Index Terms-Dielectric waveguide, THz integrated circuit, Silicon-on-Glass (SOG) waveguide.