The present invention relates to an interdigitated microelectrode biosensor using the reaction between receptors and target biomaterials, the interdigitated microelectrode biosensor comprising: an insulating layer formed so as to cover all of the sensor formation area of a substrate; a first interdigitated microelectrode formed such that a plurality of first protruding electrodes are arranged in a comb shape on the insulating layer of the substrate; a second interdigitated microelectrode, facing the first interdigitated microelectrode and formed such that a plurality of second protruding electrodes are arranged in a comb shape on the insulating layer of the substrate such that the plurality of second protruding electrodes are arranged to respectively interdigitate with the plurality of first protruding electrodes formed at the first interdigitated microelectrode; and a plurality of receptors arranged in the space between the first and second interdigitated microelectrodes, which are arranged to interdigitate with each other, so as to specifically react with the target biomaterial, thereby increasing an impedance detection width and detection limit, and improving detection accuracy according to the characteristics of each monomer and each polymer.