The present invention provides a dielectric waveguide resonator comprising a pair of rectangular parallelepiped-shaped dielectric blocks being in contact with each other through respective contact surfaces thereof. The dielectric waveguide resonator has an outer periphery coated with an electrically conductive film except for the contact surfaces, and is configured to resonate in a TE mode. A probe composed of an electrically conductive film is formed on at least one of the contact surface. Thus, it becomes possible to provide a dielectric waveguide resonator having a simple structure, requiring no adjustment structure, and comprising a structure for conversion between a dielectric waveguide and a coaxial line.