Provided is a syringe and a mounting tool capable of facilitating the delivery of a target amount selectively only when necessary. An outer cylinder (110) that can be filled with liquid, and a plurality of recesses (126B) that are movable in the outer cylinder (110) along the longitudinal direction of the outer cylinder (110) and are arranged in the longitudinal direction； A pusher (120) formed with a convex portion (126A), and projections (132A), (132B), which are slidably in contact with at least the convex portion (126A) in accordance with the movement of the pusher (120), And a rotation restricting portion (133) that contacts the pusher (120) and restricts the rotation of the pusher (120) with respect to the outer cylinder (110), and has an annular shape that can be attached to the outer cylinder (110). A syringe (100) having a mounting tool (130).必要な場合にのみ選択的に、目的の量の送液を容易にすることが可能なシリンジおよび装着具を提供する。内部に液体を充填可能な外筒（１１０）と、前記外筒（１１０）内で当該外筒（１１０）の長手方向に沿って移動可能であり、長手方向に並ぶ複数の凹部（１２６Ｂ）および凸部（１２６Ａ）が形成された押し子（１２０）と、前記押し子（１２０）の移動に伴い少なくとも前記凸部（１２６Ａ）と順次滑動可能に接触する突起部（１３２Ａ），（１３２Ｂ）、および前記押し子（１２０）と接して当該押し子（１２０）の前記外筒（１１０）に対する回転を規制する回転規制部（１３３）を備え、前記外筒（１１０）に装着可能な環形状の装着具（１３０）と、を有するシリンジ（１００）である。
