A thread-fixing tool includes a first member in which a lumen opened at an end surface through which a suture thread is inserted, and a communication path having a first end opened at the end surface and a second end in communication with an intermediate portion of the lumen are formed, and a second member having a shaft portion inserted into the communication path of the first member, and a pressing portion which is formed at a distal portion of the shaft portion and which is capable of deforming outwardly in a radial direction of the shaft portion, wherein the pressing portion is guided to the intermediate portion of the lumen through the communication path, and deformed in a direction crossing an insertion direction of the suture thread to push the suture thread against an inner wall of the lumen.