An end of a rocker arm proper is formed into a stepped shape and includes a base section and a mounting section projecting outwardly from the base section. A ceramic tip and a soldering or brazing metal have the same plane figure as the mounting section. The ceramic tip is soldered or brazed to the mounting section by means of a continuous furnace. During conveyance by a conveyor to and from the continuous furnace, the ceramic tip and the soldering or brazing metal are held in place on the mounting section by a jig. The jig is in the form of a framework and adapted to be installed on the base section and fittingly receive therein the mounting section. The jig is also adapted to fittingly receive therein the ceramic tip and the soldering or brazing metal.