A liquid medicine administration device (10) includes: a cylinder (12) filled with a liquid medicine (M), a gasket (34) placed inside the cylinder (12)； an advancing mechanism (36) configured to advance the gasket (34) in a distal direction； a drive mechanism (42) including a motor (40) that is configured to drive the advancing mechanism (36)； a battery (26) configured to supply power to the motor (40)； and a control unit (28) configured to control a rotational speed of the motor (40). In a first movement section that is an initial sliding section included in an advancing movement of the gasket (34) in the cylinder (12), one cycle including one continuous rotation and one continuous stop of the motor (40) is repeated two or more times.
