PROBLEM TO BE SOLVED: To provide a treatment material capable of preventing an excessive tissue formation by suppressing the growth of cells related to repairing mechanism in the healing and repairing process after damage of a biological tissue, particularly to a treatment material capable of keeping the lumen open state of a tubular tissue such as blood vessel over a long period by suppressing the excessive growth of emergent tunica intima by the damage repairing mechanism after the luminal expansion using a stent related to the treatment of a luminal stenotic part in the tubular tissue, and a stent containing this treatment material. SOLUTION: This in vivo self-retaining iodine releasing treatment material comprises an iodine-containing compound and releases iodine by contacting with humor. This stent is a preferable embodiment thereof. The stent may comprise a cover material.
