PROBLEM TO BE SOLVED: To provide a medical device and an infusion set capable of suppressing leakage of a fluid in inside, even when inner pressure on a position where tubes are connected through a tube for connection.SOLUTION: A medical device of the invention comprises: a first tube a second tube which has a seal part whose outer diameter is larger than an inner diameter of the first tube in a natural state, and has a tubular tip part inserted into the first tube and a tubular base end part continuous to the tip part and a third tube which is inserted into the base end part from a base end opening of the second tube.SELECTED DRAWING: Figure 2COPYRIGHT: (C)2018,JPO&INPIT【課題】連結用の管を介して管同士が連結した箇所の内圧が上昇しても、内部の流体が漏れ出すことを抑制できる医療器具及び輸液セットを提供する。【解決手段】本発明の医療器具は、第1管と、自然状態で前記第1管の内径よりも大きい外径を有するシール部を有し前記第1管内に挿入されている管状の先端部と前記先端部に連なる管状の基端部とを有する第2管と、前記第2管の基端開口から前記基端部内に挿入されている第3管と、を備える。【選択図】図2
