Abstract: Co/Cu/FeNi three terminal device with dimension of 5μm×5μm was prepared by magnetron sputtering and photolithography. The relationship between voltage output and applied magnetic field at different injection current. The results show that the sample has spin-related dipolar output signal. The output signal reaches 17μV. The relationship between voltage output and injection current was measured as well. It is found that the relationship is linear when injected current is small, however, it becomes nonlinear when the injected current increases to large value.