A process for metallizing the surface of a ceramic is provided. The surface of a ceramic is coated with a mixture of SiO.sub.2 and at least one copper compound selected from the group consisting of copper carbonate, copper sulfate, copper sulfide, copper oxide, and copper chloride. Thereafter, the film is heated at 900.degree. to 1300.degree. C. in an oxidizing atmosphere to form a baked layer on the surface of the ceramic. The ceramic having the baked layer formed thereon is subjected to a reduction treatment to form a copper-metallized layer on the surface of the ceramic.