PURPOSE: To enable accurate analysis and measurement, by a method wherein the surface of a solid sample is purified in a vacuum sample chamber beforehand and then, the surface of at least a part of the solid sample is coated with a conductive material without exposure of the sample to atmospheric air.

CONSTITUTION: A sample holder 3 and a target 4 are held on a fixed plate 5 in a vacuum sample chamber 8 and the fixed plate 5 is made rotatable centered on a rotating shaft 6. A shielding plate 7 is provided to prevent the coating of the surface of the target 4 with particles sputtered during a sputter etching of the solid sample 2. After the sputtering within the vacuum sample chamber 8, the surface of the target is further coated with a conductive material without exposure of the solid sample 2 to atmospheric air to form at least one conductive layer, thereby enabling accurate analysis and measurement.