PROBLEM TO BE SOLVED: To enable to observe the bottom of a contact hole or inside wiring. SOLUTION: In observing a contact hole 102, positive charges 106 are produced at the surface of an insulating material 101, and then, secondary electrons 104 are attracted from inside the hole in this electric field. In a wiring embedded in the insulating material, an electron beam is made to be intruded into a sample, and then, the existence of the wiring is reflected as a change in charging quantity at the surface, to be thus observed. Specifically, prior to the observation, the surface of the sample is irradiated for a predetermined period at an accelerating voltage which is different from an accelerating voltage at the time of the observation and actively produces positive or negative charges. Thereafter, the accelerating voltage is returned to a value suitable for the observation, and then, the observation is carried out.
