This treatment tool (7) has a first gripping member (10) and a second gripping member (11). A thermoplastic resin staple (12C) is accommodated in the first gripping member (10). A recess section (110) is formed in a gripping surface (111) of the second gripping member (11). A heating member (17) is installed on the bottom of the recess section (110). Living tissue (LT) is gripped between a gripping surface (101) of the first gripping member (10) and the gripping surface (111) of the second gripping member (11). When the staple (12C) is ejected from the first gripping member (10), a needle (122) of the staple (12C) penetrates the living tissue (LT). The tip of the needle (122) enters the recess section (110), and is heated by the heating member (17) and deformed. Accordingly, an anchor section (123C) is formed on the tip of the needle (122). The temperature of a region (Ar1) inside the recess section (110) is higher than that of a region (Ar2) outside the recess section (110). Therefore, it is possible to suppress the temperature of the entire second gripping member (11) from rising when forming the anchor section (123C) on the tip of the needle (122).La présente invention concerne un instrument de traitement (7) comportant un premier élément de préhension (10) et un second élément de préhension (11). Une agrafe en résine thermoplastique (12C) est logée dans le premier élément de préhension. Une section évidée (110) est formée dans une surface de préhension (111) du second élément de préhension (11). Un élément chauffant (17) est installé sur le fond de la section évidée (110). Un tissu vivant (LT) est saisi entre une surface de préhension (101) du premier élément de préhension (10) et la surface de préhension (111) du second élément de préhension (11). Lorsque lagrafe (12C) est éjectée du premier élément de préhension (10), une aiguille (122) de lagrafe (12C) pénètre dans le tissu vivant (LT). La pointe de laiguille (122) pénètre dans la section évidée (110), et est
