A drug solution administration apparatus includes an injection unit comprising an injection member configured to inject a drug solution; a delivery unit configured to be coupled to and decoupled from the injection unit, the delivery unit comprising: a delivery member configured to deliver the drug solution to the injection member, and a delivery device configured to deliver the drug solution to the delivery member; a detection unit configured to detect whether the injection unit and the delivery unit are coupled or decoupled; and a control unit configured to control operation of the delivery device. The control unit is configured to perform at least one of (i) restricting the filling operation when the detection unit detects that the injection unit and the delivery unit are coupled, or (ii) restricting the administration operation when the detection unit detects that the injection unit and the delivery unit are decoupled.