A grasping and treating device (1) has a treating section (13) at the distal end of a rod member (6) for transmitting ultrasonic vibration. The treating device (1) further has a grasping piece (21) for grasping organism tissue between the grasping piece (21) and the treating section (13). A holder member (41) is mounted to the jaw (35) of the grasping piece (21). A pad member (61) is inserted in a recess (51) in the holder member (41). The pad member (61) is formed from a resin material and is straight in a natural state. Consequently, the member (61) can be manufactured easily and at low cost by cutting or extrusion molding. Inserting the pad member (61) into the recess (51) causes the pad member (61) to be elastically deformed along the sloped surface (63) of the holder member (41). As a result, a sloped surface (65) is created at the distal end of the pad member (61). The sloped surface (65) and the sloped surface (28) of the treating section (13) prevent tissue from slipping down from between the treating section (13) and the grasping piece (21). Tissue grasped between the treating section (13) and the grasping piece (21) is incised and coagulated by ultrasonic vibration.Un dispositif de préhension et de traitement (1) comporte une partie de traitement (13) à l'extrémité distale d'un élément de tige (6) pour transmettre une vibration ultrasonique. Le dispositif de traitement (1) comporte en outre une pièce de préhension (21) pour saisir un tissu d'organisme entre la pièce de préhension (21) et la partie de traitement (13). Un élément de maintien (41) est monté sur la mâchoire (35) de la pièce de préhension (21). Un élément tampon (61) est inséré dans un évidement (51) dans l'élément support (41). L'élément tampon (61) est constitué d'un matériau de résine et est droit à l'état naturel. Par conséquent, l'élément (61) peut être fabriqué facilement et à faible coût par découpe ou moulage par extrusion. L'insertion de l'élément tampon (61) dans l'évidement (51) amèn
