A liquid medicine administration device includes: a cylinder filled with a liquid medicine, a gasket located inside the cylinder； an advancing mechanism configured to advance the gasket in a distal direction； a drive mechanism including a motor configured to drive the advancing mechanism； a battery configured to supply power to the motor； and a control unit configured to control a rotational speed of the motor. In a first movement period that is an initial sliding period included in an advancing movement of the gasket in the cylinder, a cycle including one continuous rotation and one continuous stoppage of the motor is repeated two or more times.
