To increase the electric conductivity, thermal conductivity and heat resistance of a material and to improve its impact resistance to arc discharge by providing it with a primary layer composed of Cu or the alloy thereof and a secondary layer composed of a Cu-Cr series composite material joined thereto.

The electric conductivity of the primary layer is preferably regulated to ≥60% IACS. The thickness h1 of the primary layer and the thickness h2 of the secondary layer preferably satisfies the relation of 0.2≤h1/(h1+h2)≤0.8. The thickness of the secondary layer is preferably regulated to ≥65 HRB by Rockwell hardness of a B scale. Moreover, the porosity in the secondary layer is preferably regulated to ≤5 vol.%. The content of Cr in the secondary layer is preferably regulated to 25 to 60%. Furthermore, as for the compsn. of the Cu-Cr series composite material, preferably, one or more kinds among Bi, Te, Sb and chromium oxide are contained in addition to Cr, and the content thereof is regulated to 0.01 to 8%.