The present invention provides a dielectric waveguide input/output structure for connecting to a coaxial connector a plurality of dielectric waveguide resonators each comprising an approximately parallelepiped-shaped dielectric block, wherein the plurality of dielectric waveguide resonators include a first dielectric waveguide resonator and a second dielectric waveguide resonator each having an exterior coated with an electrically conductive film, except for a coupling window, wherein each of the coupling window is formed with a probe composed of an electrically conductive film, the probe having one end connected to a feeding point, and the other end connected to the electrically conductive film, and wherein the first dielectric waveguide resonator and the second dielectric waveguide resonator are arranged in such a manner that the one side surfaces thereof are located in opposed relation to each other.