Abstract: The output impedance is one of the most important parameters of the current source in the composition of the information-measuring system of electrical impedance tomography on which the metrological characteristics of the entire system depend. In this study, a setup was developed for conducting studies of the output impedance of the current source in a given amplitude range and frequency of the output current. Studies of the output impedance of the current source were carried out as a result, a characteristic was obtained, the use of which will further help to improve the design of the device for electrical impedance tomography.