A radio frequency filter employing a dual notch structure, comprising: a first cavity including a first resonator, a second cavity including a second resonator, a third cavity including a third resonator, and a fourth cavity including a fourth resonator, wherein the first cavity, the second cavity, the third cavity and the fourth cavity are arranged in a metal housing and are sequentially coupled; an input connector to receive an input signal and an output connector to provide an output signal; the first resonator of the first cavity is connected with the input connector and the fourth resonator of the fourth cavity si connected with the output connector a Capacitor, C, type notch structure formed in a predetermined region on a partition interposed between two cavities (11, 14) to be cross-coupled, the C type notch structure comprising a metal stick forming a capacitive coupling between respective resonators (21, 23) of the two cavities (11, 14), the metal stick being installed in a cut off portion of the partition; and an Inductor, L, type notch structure formed along with the C type notch structure in another region of the predetermined region of the partition between the two cavities (11, 14), the L type notch structure being in the form of a window formed in the partition and creating an inductance coupling between the respective resonators (21, 23) of the two cavities (11, 14); wherein the L type notch structure is formed at a position nearer than the C type notch structure to the input connector for receiving an input signal and the output connector for providing an output signal; wherein the two cavities are the first cavity and the fourth cavity; and wherein the signal input to the input connector is output at the output connector after sequentially passing through the first resonator, the second resonator, the third resonator and the fourth resonator. a first cavity including a first resonator, a second cavity including a second resonator, a third cavity including a third resonator, and a fourth cavity including a fourth resonator, wherein the first cavity, the second cavity, the third cavity and the fourth cavity are arranged in a metal housing and are sequentially coupled; an input connector to receive an input signal and an output connector to provide an output signal; the first resonator of the first cavity is connected with the input connector and the fourth resonator of the fourth cavity si connected with the output connector a Capacitor, C, type notch structure formed in a predetermined region on a partition interposed between two cavities (11, 14) to be cross-coupled, the C type notch structure comprising a metal stick forming a capacitive coupling between respective resonators (21, 23) of the two cavities (11, 14), the metal stick being installed in a cut off portion of the partition; and an Inductor, L, type notch structure formed along with the C type notch structure in another region of the predetermined region of the partition between the two cavities (11, 14), the L type notch structure being in the form of a window formed in the partition and creating an inductance coupling between the respective resonators (21, 23) of the two cavities (11, 14); wherein the L type notch structure is formed at a position nearer than the C type notch structure to the input connector for receiving an input signal and the output connector for providing an output signal; wherein the two cavities are the first cavity and the fourth cavity; and wherein the signal input to the input connector is output at the output connector after sequentially passing through the first resonator, the second resonator, the third resonator and the fourth resonator.