A thread fixing tool (1) includes a first member (2) in which a lumen (5) having a first opening portion (5a) through which the suture thread (100) is inserted is formed, a second opening portion (6a) formed at different position with the first opening portion (5a) on the first member (2), and a second member (10) inserted into the first member (2) through the second opening portion (6a). Any one of the first member (2) is provided with a pressing portion (4), the pressing portion (4) being deformed in a direction crossing an insertion direction of the suture thread (100) to push the suture thread (100) against an inner wall of the lumen (5) by an insertion of the second portion (10) into the first member (2).
