PROBLEM TO BE SOLVED: To prevent an erroneous operation in which a connection between a first housing and a second housing is accidentally released in a state where a first housing and a second housing are fixed, and a sealing property in the first housing is provided. Provided is a medical device including a fixing member capable of increasing the pressure. A liquid medicine administration device (10) is connectable to and separable from a first housing (100) having a liquid supply part (110) for supplying a liquid medicine into a living body, and is attached to a body surface of a living body. The second housing 200 is provided in the first housing and the second housing, and when the first housing and the second housing are connected, the second housing 200 is operated in the first operation direction from the first housing side to the second housing side. The fixing member 300 that fixes the first housing and the second housing is included. [Selection diagram] Figure 2【課題】第１ハウジングと第２ハウジングが固定された状態で誤って第１ハウジングと第２ハウジングの接続が解除される誤操作の発生を防止することができ、かつ、第１ハウジング内のシール性を高めることができる固定部材を備える医療機器を提供する。【解決手段】薬液投与装置１０は、薬液を生体内へ送液する送液部１１０を備える第１ハウジング１００と、第１ハウジングと接続および分離可能であり、生体の体表に装着される第２ハウジング２００と、第１ハウジングおよび第２ハウジングに設けられ、第１ハウジングと第２ハウジングが接続した状態において第１ハウジング側から第２ハウジング側に向かう第１操作方向への操作に伴って第１ハウジングと第２ハウジングを固定する固定部材３００と、を有している。【選択図】図２
