In an irreversible circuit element, operation in a plurality of frequency regions is possible and low-input impedance is achieved. The irreversible circuit element is provided with first and second high-pass type isolators (1, 2) in which first and second center electrodes (35, 36) disposed so as to intersect while isolated from each other are provided to a ferrite (32) to which a direct-current magnetic field is applied by a permanent magnet. One end of the first center electrode (35) is used as an input port (P1) and the other end as an output port (P2). One end of the second center electrode (36) is used as an input port (P1) and the other end as a ground port (P3). The pass frequency band of the first isolator (1) is higher than the pass frequency band of the second isolator (2). The input parts of the isolators (1, 2) are mutually electrically connected and used as one input terminal (IN). A low-pass filter (LPF) is inserted between the input terminal (IN) and the input port (P1) of the second isolator (2).