PROBLEM TO BE SOLVED: To provide a puncture needle device for an ultrasonic endoscope in which, when a double-thread male screw arranged in a mouth ring side of the ultrasonic endoscope and a double-thread female screw arranged in the puncture needle device side are tightened, a relative rotational direction position to the mouth ring of the puncture needle device comes to the predetermined position without fail.SOLUTION: Equipped with a first female screw 32A and a second female screw 32B, in which both of root diameters in an edge part in an inlet side formed with circumferential phases mutually shifted by 180 degrees on an inner circumferential surface of a connection opening of a cylindrical connection part 31, are larger than the outer diameter of a first male screw 18A and the outer diameter of a second male screw 18B. For the first female screw 32A, the root diameter is constant up to a first end position advanced just by integer pitch with the edge part in the inlet side as a reference, for the second female screw, the root diameter, from the first end position advanced just by the integer pitch with the edge part in the inlet side as the reference to the second end position 32B4 one-pitch short of this first end position, is larger than the outer diameter of the second male screw and smaller than the outer diameter of the first male screw, moreover, the root diameter from the edge part in the inlet side to right before the second end position is constant.COPYRIGHT: (C)2013,JPO&INPIT【課題】超音波内視鏡の口金側に設けた二条の雄ねじと穿刺針装置側に設けた二条の雌ねじを締め付けたときに、穿刺針装置の口金に対する相対的な回転方向位置が必ず所定の位置になる超音波内視鏡用穿刺針装置を提供する。【解決手段】筒状接続部31の接続開口の内周面に周方向位相を互いに180°ずらして形成した、入口側端部の谷の径が共に第1の雄ねじ18Aの外径及び第2の雄ねじ18Bの外径より大きい第1の雌ねじ32A及び第2の雌ねじ32Bと、を備え、第1の雌ねじ32Aは、入口側端部を基準に整数ピッチ分だけ進んだ第1終端位置までの谷の径が一定であり、第2の雌ねじは、入口側端部を基準に整数ピッチ分だけ進んだ第1終端位置から該第1終端位置より1ピッチ手前の第2終端位置32B4までの谷の径が、第2の雄ねじの外径より大きくかつ第1の雄ねじの外径より小さく、さらに入口側端部から第2終端位置の直前までの谷の径が一定である。【選択図】図12
