PROBLEM TO BE SOLVED: To provide an operation unit for a bending treatment instrument which is inserted into an endoscope channel and is capable of being used by intuitive operation and so as to be capable of smooth bending operation.SOLUTION: An operation unit for performing operation of a treatment instrument and bending operation of a bending treatment instrument which comprises the treatment instrument at its tip and is capable of being bent freely, by being connected with a device wire connected with the treatment instrument to operate the treatment instrument and being connected with each of a plurality of bending wires for performing bending operation on the bending treatment instrument comprises: an operation unit main body a guiding unit through which the device wire penetrates a bending wire traction unit with which the bending wires are connected and which is mounted on the guiding unit so as to be freely rocked and a grip unit with which the device wire is connected and which can perform reciprocating movement in the axial center direction of the bending wire traction unit.
