A mold for use in producing an in-vivo indwelling member having a linear primary coil formed in a three-dimensional shape includes a transformable member transformable between an assembled state and an unfolded state, the transformable member has, in the assembled state, an outer portion that is arranged at an outer side and an inner portion that is arranged at an inner side of the outer portion, with being connected to the outer portion, and the outer portion and the inner portion have holding portions for holding the primary coil. The mold makes it possible to easily produce an in-vivo indwelling member having a three-dimensional shape that allows the in-vivo indwelling member to be stably arranged within a bulge such as an aneurysm.
