< Topic >Quite smooth sliding characteristic of the gasket of the syringe and liquid dense characteristic or the airtightness which is superior are guaranteed by simple constitution.SolutionsIn order to solve aforementioned topic the syringe of this invention as for (1), the barrel which fills liquid L (3) and the barrel (3) the plunger which pushes out the liquid L which was filled inside (5) and the root diameter of the aforementioned male screw (27) where the gasket (9) where the plunger (5) is installed in the point (7) and, it possesses, this touches to the inner wall surface (31) and of the female screw section (27) in order the aforementioned plunger (5) in the point (7) to install the gasket (9) and the heaven surface (29) of the gasket (9) supports the gasket (9) (D2) Compared to it provides with the support convex section (33), of small diameter the aforementioned male screw (27) and the spiral shellfish carving/moment facilities it does the female screw section (47) which is adjusted on the inside perimeter aspect of the aforementioned gasket, (9) inside diameter (D4) of the aforementioned female screw section (47) which accepts the aforementioned support convex section (33) to the heaven surface (29) compared to it provides the acceptance concave section (49) of small diameter, in position of the heaven surface (29) approaching of the peripheral aspect (37) of the aforementioned gasket (9) the barrel the 1st annulation where (3) touches with the inside perimeter aspect (14)The sudden section (39) was provided.< Selective figure >Figure 4【課題】極めて簡単な構成によってシリンジのガスケットの円滑な摺動性と、優れた液密性ないし気密性を確保する。【解決手段】前記課題を解決するために本発明のシリンジ(1)は、液体Lを注入するバレル(3)と、バレル(3)内に注入された液体Lを押し出すプランジャ(5)と、プランジャ(5)の先端部(7)に取り付けられるガスケット(9)と、を具備し、前記プランジャ(5)の先端部(7)にガスケット(9)を取り付けるための雌ネジ部(27)と、ガスケット(9)の天面部(29)の内壁面(31)に当接してガスケット(9)を支持する前記雄ネジ部(27)の谷径(D2)よりも小径の支持凸部(33)とを設け、前記ガスケット(9)の内周面に前記雄ネジ部(27)と螺合する雌ネジ部(47)を刻設し、天面部(29)に前記支持凸部(33)を受け入れる前記雌ネジ部(47)の内径(D4)よりも小径の受入れ凹部(49)を設け、前記ガスケット(9)の外周面(37)の天面部(29)寄りの位
