PURPOSE: To stamp and mold a portion to be molded such as an engaging head or the like with high accuracy by making a part of the outer peripheral face of a circular roller butt against the inner peripheral face of a ring shaped external roller, feeding nomofilament to the butting portion and molding it.

CONSTITUTION: A pair of stamping mold rollers 2, 3 are so aranged that the outer peripheral face of the circular internal roller 3 partly butts against the inner peripheral face 4 of the ring-shaped external roller 2. Then, the rollers 2, 3 are rotated in the same direction, for example, rightward, a monofilament 1 to be molded is fed between both the rollers 2, 3 and pressed and molded into a prescribed shape such as an engagement head or the like by a pressing projection 6 and a recessed portion 7. Thus, as both the rollers 2, 3 rotate in the same direction, the pressing projection 6 and the recessed portion 7 are gradually drawn near to each other and gradually press a portion to be molded 8 of the monofilament 1. Then, at the butting portion of the rollers 2, 3, a molded portion 9 is formed. After that, the pressing projection 6 and the recessed portion 7 are gradually separated from each other so that stamping mold is carried out to release the pressing force.