A bandpass filter for a wide frequency band such as UWB is disclosed. The bandpass filter can receive a pair of signals, namely a balanced signal, and output a pair of signals. The bandpass filter comprises a plurality of ½ wavelength resonance electrodes, a plurality of ¼ wavelength resonance electrodes and a plurality of coupling electrodes. A transmission characteristic of the bandpass filter having flat and low loss over the entire region of the broad pass band can be achieved.