A cutoff waveguide path is provided in a part of a dielectric waveguide comprising a pair of main conductive layers formed on an upper and a lower surfaces of a dielectric and groups of conductive vias arranged in the direction of signal transmission with a space of a distance less than ½ of a signal wavelength between the conductive vias, and provided in the cutoff waveguide path is a resonator having dielectric vias formed of a dielectric having a higher dielectric constant than that of a dielectric forming the dielectric waveguide. With this construction, a dielectric waveguide type filter easily designed and manufactured can be obtained.