Articles with a tenaciously adherent diamond coating are made by forming a diamond coating on a base material by vapor-phase synthesis without causing any warpage of the coating. The diamond coating layer is formed on the surface of a base material having a number of pores formed by electric discharge or laser beams and having a depth of 0.0001-0.2 mm and a diameter of 0.001-0.02 mm. The pores may be connected to one another to form a groove. Suitable examples of the base material include molybdenum, tungsten, silicon, tungsten carbide, silicon carbide, silicon nitride, and cemented carbide mainly comprising tungsten carbide and cobalt and/or nickel.