The present invention relates to a semiconductor test device which may use a leakage current and/or a compensation system of leakage current. The semiconductor test device, according to exemplary embodiments of the present invention, may include MOS transistors which may be fabricated in processes similar to those of the semiconductor device. The semiconductor test device may sense the leakage currents which may flow in the MOS transistors, may test whether the semiconductor device may be fabricated normally or abnormally, and may generate at least a normal or abnormal signal as a result. The leakage current compensation device may compensate for the leakage current which may flow in the semiconductor device in response to the normal or abnormal signal of the semiconductor test device. According to exemplary embodiments of the present invention, abnormally-fabricated MOS transistors may be tested and malfunctions of the semiconductor device may be reduced by the leakage current compensation device.