Treatment toolA first jaw 11 having a first gripping surfaceA second jaw 11 'having a second gripping surface 1111'Provided on a first gripping surfaceA first wiring pattern 152 having a first heating portion 1522 whose resistance value per unit length of the first jaw 11 is greater than the resistance value of other regions isThe second holding surface 1111 'is provided.A second wire pattern 152 ′ having a second heat generating portion 1522 ′ having a resistance value per unit length of the second jaw 11 'larger than the resistance value of another region is provided.The first heating portion 1522 is provided in the first region when the first holding surface 1111 is divided into two regions of the first and second regions parallel to the longitudinal direction of the first jaw 11.The second heat generating portion 1522 'is provided in a second projection area in which the second region is projected onto the second holding surface 1111 ′ in a closed state in which the first and second holding surfaces 1111 and 1111 ′ are opposed to each other.処置具２は、第１把持面１１１１を有する第１ジョー１１と、第２把持面１１１１´を有する第２ジョー１１´と、第１把持面１１１１に設けられ、第１ジョー１１の長手方向の単位長さ当たりの抵抗値が他の領域の抵抗値よりも大きい第１発熱部１５２２を有する第１配線パターン１５２と、第２把持面１１１１´に設けられ、第２ジョー１１´の長手方向の単位長さ当たりの抵抗値が他の領域の抵抗値よりも大きい第２発熱部１５２２´を有する第２配線パターン１５２´とを備える。第１発熱部１５２２は、第１ジョー１１の長手方向に沿って並列する第１，第２領域の２つの領域に第１把持面１１１１を分割した場合に、第１領域に設けられている。第２発熱部１５２２´は、第１，第２把持面１１１１，１１１１´を互いに対向させた閉状態において、第２領域を第２把持面１１１１´に投影した第２投影領域に設けられている。
