An apparatus for continuously and rapidly forming petal-like segments at the tip of a tampon inserter into a hemispherically curved shape. Sets of molds are mounted on a support table on a rotary table turned about a shaft. Each set comprises a heating mold to heat and soften the tip of the tampon inserter and a cooling mold to shape while being cooled the heated and softened tip. The heating and cooling molds are moved by a cam so that either of the two molds is placed above the tampon inserter held in position by a gripper. The gripper comprises a pair of gripper segments that are opened and closed by a cam on the shaft and raised and lowered by another cam on the same shaft. The cams are adapted to release the tampon inserter from the gripper after the tampon inserter has been put first in the heating mold and then in the cooling mold. The tip of the tampon inserter held by the gripper first enters the heating mold to get heated. While the heated tip descends temporarily, the cooling mold is brought to above the tampon inserter. As the tampon inserter rises again, its tip comes in contact with the inner surface of the cooling mold, in which the tip is formed into a hemispherically curved shape while being cooled.