PURPOSE: To drastically shorten the time for testing by integrally mounting probe assemblies consisting of plural probes via a mounting plate so as to simultaneously obtain electrical contact with all the electrodes of a display panel and providing a manipulator which can adjust the probe end positions of the individual probe assemblies.

CONSTITUTION: The electrodes corresponding to the scanning wires disposed to run the LCD panel in a cross direction are trisected to provide the probe assembly units consisting of the three. The electrodes corresponding to the signal wires disposed to run the LCD panel in the longitudinal direction are quadrisected to provide the probe assembly units consisting of the four. The four probe assembly units disposed in the longitudinal direction of the LCD panel act to provide electrical contact at both ends of the same signal wires. A disconnection in the mid-way of the signal line electrodes is easily detected by checking the conduction at both ends if such probes are disposed.