PROBLEM TO BE SOLVED: To provide a medical liquid injector capable of appropriately injecting medical liquid in a living body.SOLUTION: A medical liquid injector 1 that can puncture a punctured site and inject chemical liquid in a living body includes a puncture body 10 having a puncture needle 16, a contact part 20 having a contact surface 24b, contact detection means 29, drive means 40, and control means 60. The control means 60 causes the puncture needle 16 to be gradually protruded from the contact surface 24b by the drive of the drive means 40 in a state that the contact surface 24b is brought into contact with the punctured site, determines that the contact surface 24b is separated from the surface of the punctured site due to an increase in the amount of protrusion of the puncture needle 16 based on the detection by the contact detection means 29, and acquires information on the maximum depth from the amount of protrusion of the puncture needle 16 at this time.SELECTED DRAWING: Figure 2COPYRIGHT: (C)2017,JPO&INPIT【課題】 生体内への薬液の注入を的確に行うことができる薬液注入装置を提供する。【解決手段】 被穿刺部位に穿刺して生体内に薬液を注入可能な薬液注入装置1であって、穿刺針16を有する穿刺体10、当接面24bを有する当接部20、当接検知手段29、駆動手段40、および制御手段60を備え、制御手段60は、当接面24bを被穿刺部位に当接させた状態で、駆動手段40の駆動により穿刺針16を当接面24bから徐々に突出させ、穿刺針16の突出量の増加に伴い当接面24bが被穿刺部位の表面から離れたことを当接検知手段29の検知に基づき判定し、このときの穿刺針16の突出量から最大深さ情報を取得する。【選択図】 図2