An inter-spinous implant includes an approximately conical screw portion, further having a screw thread, which can be screwed between spinous processes； a head portion of an approximate inverted frustum shape of the same axis as the screw portion； a spacer portion that is formed between the screw portion and the head portion in the axial direction； and a through hole that passes through the axial center of the screw portion, the spacer portion, and the head portion. At least one slit is formed in the major axial direction of the total shape of the implant, having at least one-third the length of the total length of the major axial direction, the depth whereof reaching the through hole. Disposing the slit in the major axial direction of the implant proper imparts flexibility and elasticity to the implant overall, simplifies the installation and insertion of the implant.
