This study conducted the forward modeling of a 3D good conductor model under a uniform half-space background to investigate its response characteristics in a plane electromagnetic wave survey. The electromagnetic anomalies of a three-dimensional good conductor are primarily caused by the secondary field generated by static charge accumulated at interfaces. Consequently, higher relative resistivity differences between the target conductor and the surrounding rock correspond to greater response anomalies. Additionally, a smaller distance between observation electrodes and the target conductor is associated with greater relative response anomalies. Changes in the horizontal and vertical dimensions of a conductor pose different impacts of anomalies. Specifically, variations in vertical thickness have minor impacts on the anomalies. When a conductor has similar dimensions in the horizontal direction, its apparent resistivity response curve resembles a two-layer D-type sounding curve, with the relative anomalies intensifying as the horizontal sizes increase. However, in the case of significant differences between the two dimensions in the horizontal direction (with the larger dimension being at least eight times the smaller), the response curves observed in the directions of the larger and smaller dimensions differ. Notably, the apparent resistivity response curve observed in the direction of the larger dimension resembles a three-layer H-shaped sounding pattern characterized by high, low, and high values sequentially. In addition, the relative anomalies of apparent resistivity are generally more than two times those of phase, with apparent resistivity anomalies following the static effect law in the vertical direction. Specifically, apparent resistivity anomalies in high frequencies tend to extend to low frequencies, creating favorable conditions for anomaly identification. Therefore, apparent resistivity anomalies are more conducive to anomaly identification for good conductors.