to provide a compact and / or lighter capable of realizing the technology of liquid injector of the driving mechanism. Liquid injector (110) is for the purpose of injecting liquid medicine into a patient, a plurality of stator members (162) which strip electrodes are formed and a plurality of strip-shaped electrodes are formed opposed to said stator member by having a mover member (161), by utilizing an electrostatic force, and an electrostatic actuator for relatively moving the mover member (161) relative to the stator member (162) (125), the electrostatic and a drive mechanism having a movable member (121) that is moved by the driving force of the electric actuator (125).薬液注入装置等の駆動機構の小型化および/または軽量化を実現可能な技術を提供する。薬液注入装置(110)は、患者に薬液を注入するためのものであって、複数の帯状電極が形成された固定子部材(162)および複数の帯状電極が形成され前記固定子部材に対向配置された可動子部材(161)を有し、静電力を利用して、可動子部材(161)を固定子部材(162)に対して相対的に移動させる静電アクチュエータ(125)と、その静電アクチュエータ(125)の駆動力によって動かされる可動部材(121)を有する駆動機構とを備える。
