In a characteristic test apparatus for an electronic device, a number of voltage supply beams are radiated onto predetermined irradiation positions of the electronic device placed on a sample table. In addition, a potential measuring beam is radiated onto a number of irradiation positions including the predetermined irradiation positions of the voltage supply beams. A secondary electron signal based on the potential measuring beam is detected to measure a potential. When the irradiation position of the potential measuring beam coincides with that of the voltage supply beam, the voltage supply beam is controlled to adjust a potential at the irradiation position to a set value by controlling, e.g., an acceleration power source for the voltage supply beam. When the irradiation position of the potential measuring beam is different from that of the voltage supply beam, a potential at this position is measured. Then, characteristics of the electronic device are calculated based on the obtained potentials at the respective irradiation positions.