The present invention relates to an in vivo indwelling member which has a shape complicatedly curved in various directions and can easily spread inside an aneurysm, while adhering to an inner wall of the aneurysm to prevent falling off therefrom, improving an indwelling density, and maintaining good operability. Shapes of two or more three-dimensional portions (middle solid 4A, large solid 4B) are provided in a primary coil 11. Each three-dimensional portion is formed by continuously providing at least four curved parts (51a to 51e/52a to 52f) over four planes. Normal directions of the four planes each have a relationship perpendicular to a predetermined common axis (a1/a2) direction. Each of the at least four curved parts (51a to 51e/52a to 52f) is formed on any of the respective planes of a quadrangular virtual cylindrical body as seen from the common axis (a1/a2) surrounded by the four planes.
