PROBLEM TO BE SOLVED: To provide an embolic coil which is hard to buckle and can be easily manufactured. An embolic coil (1) that can be introduced into an aneurysm (A) using a catheter (3) by winding a wire (2) in a direction in which a winding axis direction matches a length direction (Y) of the embolic coil (1). It has a portion in which the large-diameter coil portions 7 and the small-diameter coil portions 9 are alternately formed by making the winding diameter of the strand 2 different, and the winding diameter D1 of the large-diameter coil portion 7 is The embolic coil 1 is 12 times or less the wire diameter d of 2 and the winding diameter D2 of the small diameter coil portion 9 is 3 times or more the wire diameter d of the wire 2. [Selection diagram] Figure 2【課題】座屈しづらく簡単に製造できる塞栓コイルを提供する。【解決手段】カテーテル３を使用して動脈瘤Ａ内に導入可能な塞栓コイル１であって、巻き軸方向が該塞栓コイル１の長さ方向Ｙと一致する方向に素線２を巻くことにより構成され、素線２の巻き径を異ならせることにより、大径コイル部７と小径コイル部９とが交互に形成される部分を有し、大径コイル部７の巻き径Ｄ１は、素線２の線径ｄの１２倍以下であり、小径コイル部９の巻き径Ｄ２は、素線２の線径ｄの３倍以上である塞栓コイル１。【選択図】図２
