PURPOSE: To detect the end of a change in analytical characteristic and to measure the voltage of a sample correctly without simply adding and averaging a series of analytical voltages when correcting the analytical voltages of the equipment and eventually to increase a reliability of the test.

CONSTITUTION: This is a test equipment wherein a semiconductor integrated circuit device, an object to be tested 16, is inserted into a socket 6A exposed to the air and a terminal to be measured 16B which is extended from the socket 16A is installed in a vacuum and electron beam 11A is cast on the terminal to be measured 16B to test the object to be tested 16. This equipment is provided with an electron generator 11, a deflecting system 12, a detector 13, an analyzer 14 and a control 15. The control 15 is provided with a correcting and controlling device 15A which corrects and controls an analytical characteristic based on the detection result of the state of a change in analytical characteristic.