The present invention aims at providing a front end component of a medical device capable of suppressing catching the like during removal of the medical device with a simple configuration, therefore, the convex formed on the outer periphery of substantially circular and the outer peripheral portion a shape consisting of a part 12b having a possible inner diameter to accept the member 12 to the outer diameter shape, and a proximal end 11x having an outer diameter formed on the outer diameter shape substantially similar shape, the maximum outer diameter of the proximal portion and it is essential to outright toward the tip portion from above or the front end portion 11y of the substantially cylindrical shape having an outer diameter of the maximum outer diameter substantially the same diameter of the proximal portion, is formed in a portion corresponding to the convex portion base end portion and it is formed with a notch and a portion 11b of the shape.本発明は、簡単な構成で医療用具の抜去時の引っ掛かり等を抑止し得る医療用具の先端構成部材を提供することを目的とし、そのために、略円形の外周部と外周部に形成した凸状部12bとからなる形状を外径形状とする部材12を受け入れ可能な内径を有し、外径形状と略相似形状に外径が形成された基端部11xと、基端部の最大外径以上若しくは前記基端部の最大外径と略同径の外径を有する略円筒形状の先端部11yと、凸状部に対応した部位に形成され基端部から先端部に向けて切り欠かれた形状の切欠部11bとを備えて形成されている。
