A reciprocating mechanism 8 includes a worm shaft 20, a slider 23, a first guide shaft 21, and an elastic member 24. The worm shaft 20 includes spiral grooves 20a, and is rotated while the handle 2 is rotated. The slider 23 is reciprocated in the axial direction together with the spool shaft 5 in conjunction with the rotation of the worm shaft 20. The first guide shaft 21 includes a first supporting portion 27 and a second supporting portion 28, and guides the reciprocating movement of the slider 23 by an intermediate portion 29 between the first supporting portion 27 and the second supporting portion 28. The elastic member 24 is mounted on the outer perimeter of at least one of the first supporting portion 27 and the second supporting portion 28, and supports the first guide shaft 21 in the reel body 1.本發明之課題在於，於紡車捲線器的往復移動機構及具備此機構之紡車捲線器中，抑制往復移動機構進行往復移動時所產生之滑塊與導軸之間之晃動。 本發明之往復移動機構8具備蝸桿軸20、滑塊23、第1導軸21、及彈性構件24。蝸桿軸20具有螺旋狀槽20a，且伴隨把手2之旋轉而旋轉。滑塊23與蝸桿軸20之旋轉連動地與捲線筒軸5一併於軸向上往復移動。第1導軸21具有第1支持部27及第2支持部28，且於第1支持部27與第2支持部28之間之中間部29引導滑塊23之往復移動。彈性構件24安裝於第1支持部27及第2支持部28之至少任一者之外周，將第1導軸21支持於捲線器本體1。
