The present invention provides a drug solution administration apparatus capable of discriminating between a failure of a drive mechanism such as a motor and a blockage of a circulation part constituting a flow path. SOLUTION: The drug solution administration apparatus 100 according to the present invention stops the liquid transfer from the liquid transfer pipe 142 when the output from the rotation detection unit 132 is not included in the detection area, and the rotation reverse to that of the liquid transfer. If the output of the rotation detection unit 132 is included in the detection area while the motor 136 is rotated in the direction, it is determined that the liquid feed pipe 142 or the cannula 113 and the support member 114 are blocked, and the output is included in the detection area If not, it is determined that the drive mechanism 131 has a failure. [Selected figure] Figure 9【課題】モータなどの駆動機構の故障と流路を構成する流通部の閉塞とを判別できる薬液投与装置を提供する。【解決手段】本発明に係る薬液投与装置１００は、回転検出部１３２からの出力が検出領域に含まれない際に送液管１４２からの送液を停止し、送液の際と逆の回転方向にモータ１３６を回転させた状態で回転検出部１３２の出力が検出領域に含まれれば送液管１４２またはカニューレ１１３および支持部材１１４に閉塞が生じていると判断し、出力が検出領域に含まれなければ駆動機構１３１に故障が生じていると判断する。【選択図】図９
