PURPOSE: To form a dowel which is longer than a conventional case, with high accuracy and without generating a crack, by executing press-working for thinning an area of a dowel head part from a side where a dowel of a metallic plate projects, and after that, forming a dowel.

CONSTITUTION: A thin-walled part 14 is formed on an electrode plate 13 by a plane of a die 11 and a tip of a punch 12, of a metallic die set installed to a press machine. The circumference of the thin-walled part 14 becomes thicker inclinedly, and a swell 15 is formed. Subsequently, the electrode plate 13 on which the thin part 14 has been formed is inserted between a die 21 and a punch 22 so that the swell 15 is opposed to the die, and a dowel 23 is press-formed by operating the metallic die set. That is, on an area corresponding to the head part of the dowel 23, the thin part 14 is formed, the swell 15 formed by this excess metal is crushed and becomes a part of the dowel 23 when forming the dowel 23, breaking force generated in a boundary of the dowel head part drops remarkably, and generation of a crack is prevented.