In this study, a simple, label-free, electrochemical immunosensor system, including a three-electrode transducer and a microchamber, was designed, fabricated, and integrated with focus toward the detection of Newcastle disease virus (NDV). The chicken egg yolk antibodies (IgY) against NDV were used as the biological recognition element, replacing purified IgG antibodies that require a complex extraction process and time-consuming. The IgY against NDV was immobilized on the sensor surface using PrA/GA and SAM/NHS approaches. The immunosensor showed high sensitivity with NDV concentrations ranging from 106 to 102 EID50/mL with good specificity, repeatability, and small standard deviations. Compared to traditional methods, the immunosensor with advantages such as simple fabrication, quick response, direct detection, and possibility for miniaturization by integrating the immunosensor with the microchamber is potential for applications in contamination studies and field measurements.