PROBLEM TO BE SOLVED: To provide a dual-band resonator that has a high flexibility of design and that can be downsized, and to provide a dual-band bandpass filter using the same.SOLUTION: A dual-band resonator is configured by adding an edged end short-circuit stub 11 to a half-wavelength resonator 10. In the dual-band resonator, the half-wavelength resonator 10 is a resonator according to an odd mode, and the half-wavelength resonator 10 and the edged end short-circuit stub 11 are a resonator according to an even mode. A resonator length is adjusted so that the odd mode is resonated at a high-frequency side and an even mode is resonated at a low-frequency side, or alternatively, a resonator length is adjusted so that the odd mode is resonated at a low-frequency side and the even mode is resonated at a high-frequency side. The dual-band bandpass filter can be configured by using the dual-band resonator.
