Disclosed herein is an intracorporeally indwelling device for embolization, which is capable of being placed surly in an appointed site, capable of permiting surely performing a replacing operation of the intracorporeally indwelling device arranged once, and thus has high safety and high operating ability.The intracorporeally indwelling device for embolization of the invention comprises a flexible coiled body and an axial extension-controlling member having specified tensile break strength and provided in the interior of the coiled body so as to extend in an axial direction of the coiled body. The axial extension-controlling member is made up of a wire material having tensile break strength of at least 700 N/mm2 in the axial direction of the coiled body and a diameter of at most 25 µm.
