Disconnection defects, short-circuit defects and the like in wiring patterns of submicron sizes within TEGs (a square of 1 to 2.5 mm for each) numerously arranged in a large chip (a square of 20 to 25 mm) can be inspected with respect to all the TEGs, with good operability, high reliability and high efficiency. A conductor probe for applying voltage to the wiring patterns by mechanical contact is composed of synchronous type conductor probe that synchronizes with movement of a sample stage (16), and fixed type conductor probe means (21) that is relatively fixed to an FIB generator (10). Positions of probe tips are superimposed to an SIM image and displayed on a display unit (19).