A first electrode part in a rod shape is placed on an upper side, and a second electrode part in a rod shape having a higher melting point than that of the first electrode part is placed on a lower side, so that ends of the first and second electrode parts are brought into contact. Contact ends or vicinities thereof are irradiated with a laser beam, so that the electrode parts are welded. Here, a region irradiated with the laser beam is in a long narrow shape having a minor axis directed in a vertical direction and a major axis directed in a horizontal direction. This makes it possible to manufacture an electrode with a consistent high quality with a high yield.