To provide a small-sized and inexpensive irreversible circuit element having superior characteristics that can always maintain sure and safe connections, even when temperature is applied to the irreversible circuit element and obtains a large attenuation at a prescribed frequency band, and to provide a communication unit employing the irreversible circuit element.

A conductive adhesive is used to respectively connect an upper yoke 2 and a lower yoke 8, grounding part of a lower face of a magnetic assembly 5 and the lower yoke 8, port sections P1, P2 of center conductors 51, 52 and hot side electrodes of capacitors C1, C2 and input output terminals 71, 72, port section P3 of a center electrode 53 and hot side electrodes of a capacitor C3 and a termination resistor R, and cold side electrodes of the capacitors C1-C3, cold side electrodes of the termination resistor R and a grounding terminal 73.