To provide a component fixing structure capable of repetitively and reliably fixing a fixed member with a fixing member while preventing the fixing member from falling off the base member.SOLUTION: The component fixing structure includes a nozzle hole 23a provided along the direction of the hard portion long axis a2 and a distal end rigid portion 21 provided with a fixing member hole 26 communicating with the nozzle hole 23a An endoscope nozzle 5 having an outer circumferential groove 5e formed therein a rigid part longitudinal axis a2 of the distal end rigid part 21 and the endoscope nozzle 5 which is inserted into the fixing member hole 26 and disposed in the outer circumferential groove 5e, A fixing member 8 which fixes the relative position in the direction of the fixed member 8 and when it is applied to the fixing member 8 in a direction to pull it out of the fixing member hole 26 with respect to the fixing member 8, And a protruding protrusion 8 a that regulates the movement of the fixing member 8.(FIG.【課題】固定部材が基盤部材から脱落することを防止しつつ、固定部材によって被固定部材を繰り返し確実に固定可能な部品固定構造を提供する。【解決手段】部品固定構造は、硬質部長手軸a2方向に沿って設けられているノズル用孔23a、および、ノズル用孔23aに連通する固定部材用孔26が設けられている先端硬質部21と、外周溝5eが形成された内視鏡ノズル5と、固定部材用孔26に挿入されて外周溝5e内に配置されて先端硬質部21と内視鏡ノズル5との硬質部長手軸a2方向の相対位置を固定する固定部材8と、固定部材8に設けられ、固定部材8に対して固定部材用孔26から抜去させる方向の力が作用された際に先端硬質部21に当接して固定部材8の移動を規制する突出した突出部8aと、を備える。【選択図】図4F