PURPOSE: To form a metal probe wherein the radius of curvature of its tip is sufficiently small and its surface is hard to oxidize by a method wherein the probe is constituted of a metallic main body and of an oxidation-preventing layer with which the main body is covered.

CONSTITUTION: For example, linear tungsten having a diameter of about 0.5mm is worked to be a probe shape by a mechanical polishing method so as to have a polished angle of about 20°, and a probe main body is formed. The main body is degreased and cleaned by Freon, triethylene or the like, it is immersed in a gold plating liquid at a liquid temperature of about 100°C for about 30 minutes, and a gold thin film is formed on the surface by an electroless plating method. Thereby, it is possible to obtain a probe whose tip is sharp, which is provided with a desired radius of curvature and whose surface is hardly oxidized. Consequently, since the probe can be maintained in a state that an electric characteristic is good, it can measure a sample with high resolution, the life of the probe can be made long and its cost can be reduced.