A treatment device for endoscope includes a flexible sheath, an operation wire that is advanceably/retreatably inserted into the sheath, a treatment part comprising at least one elastic wires that can enter and exit a tip side inner part of the sheath, and a connecting member that secures to each other a tip of the operation wire and ends of the elastic wires. The connecting member includes a cylindrical body part, and a plurality of walls that extend from one end face of the body part in the direction of the axis of the body unit. A proximal end of the operation wire is secured to the body part, and the plurality of ends of the elastic wires are secured to the wall in the direction of the axis; when viewed from the wall side in the direction of the axis, at least one of the ends of the elastic wires overlaps with the body part. The interval between mutually adjacent walls is narrower than the outer diameter of the elastic wires.