Аннотация:I-V-characteristics of an irradiated transistor in many cases should be measured inside the radiation chamber with long cables, which introduces noticeable measurement error. In this paper IV-characteristics of an irradiated bipolar junction transistor measured with the 4-wire and the 2-wire circuits are presented and compared to direct (without cables) measurements. Significant enlargement of measurement error for the 2-wire method in comparison with the 4-wire method is shown for different currents.