An endoscope treatment instrument provided with a flexible transmitting member, a treatment portion that is attached to the distal end of the transmitting member, and an actuator which is attached to the proximal end of the transmitting member and is for operating the treatment portion, this endoscope treatment instrument being designed to transmit the action of the actuator to the treatment portion via the transmitting member. The transmitting member consists of the connection in the longitudinal direction of a first coil sheath that has excellent rotation follow-up and good relative bending properties, and a second coil sheath that has excellent rotation follow-up and good ease of motion in the relative longitudinal direction.