In a probe structure which has a bump contact protruded from one surface of an insulating substrate, the bump contact is deposited such that a surface roughness falls within a predetermined range specified by Rmax within a range from 0.01 to 0.8 &mgr;m, Ra within a range from 0.001 to 0.4 &mgr;m, and a ratio of Rmax/Ra within a range from 2 to 10. Such a surface roughness is realized by depositing a convex/concave layer formed by aggregation of fine grains. The convex/concave layer is directly deposited to a basic shape portion without any intermediate layer left between the convex/concave layer and the basic shape portion.