The invention provides an operational wire connection device which has a pair of semicircular fixing parts, a circular outer screw part and a connecting body, and an endoscope. The fixing parts clamp the end portion of a wire from both sides. The outer screw part has an imbedding portion for accommodating the pair of the fixing parts in the state clamping the wire, and male threads formed on the outer circumferential surface thereof. The connecting body has formed thereon female threads matching with the male threads. During adjusting of looseness of the operational wire, the pair of the fixing parts is drawn out from the outer screw part after the outer screw part is dissembled from the connecting body. After the position of the pair of the fixing parts clamping onto a passive wire has changed, the pair of the fixing parts is embedded in the outer screw part, which is then in thread connection with the connecting body.
