A semiautomatic measurement system has been developed for evaluating the electronic structure of the interface between an insulator and a semiconductor. The associated microcomputer possesses advanced software which leads to simple operation particularly when used in a real-time mode. An attractive feature of the technique is that admittance data are evaluated in the voltage domain using a modified version of the Simonne method. The Si-SiO2junction has been used to demonstrate this novel approach although it is equally applicable to other semiconductor-insulator structures.