Semiconductor testing apparatus

This invention relates generally to semiconductor testing apparatuses of the EOS (Electro-Optic Sampling) type for measuring voltages and/or electric fields by making use of the electro-optic effect, and more particularly to such a semiconductor testing apparatus which is capable of carrying out a measurement in terms of one-dimensional distribution and/or simultaneous measurements at a plurality of positions. A semiconductor testing apparatus capable of displaying its measurement results in an easily understandable manner is provided. The apparatus comprises a display section for displaying a measurement result of a change in time of a voltage distribution on a measurement plane of a measured device and an input section for entering parameters for the display of the measurement result. When a measurement time is entered as a parameter, the display section displays the measurement result by means of a three-dimensional graph and a representation in numerals, letters or symbols of the measurement time. The graph shows along its three axes a first coordinate in a first direction on the measurement plane, a second coordinate in a second direction which is perpendicular to the first direction, and a voltage at the measurement time at a position on the measurement plane defined by the first and second coordinates.