The chemical solution administration device includes a rapid administration unit (110) for a chemical solution. The rapid administration part (110) is connected between the inflow channel (111), the outflow channel (112), and the inflow channel (111) and the outflow channel (112), and stores the chemical solution. And a controller (114) for controlling the storage of the chemical liquid to the chemical liquid storage section (113) and the delivery of the chemical liquid from the chemical liquid storage section (113). The inflow channel (111) includes a first channel (111A) and a second channel (111B) having a smaller channel cross-sectional area than the first channel (111A), and a control unit ( 114) includes a first closing part (141) for closing the first flow path (111A) and a second closing part (142) for closing the outflow flow path (112) so as to be openable and closable. Yes.薬液投与装置は、薬液の急速投与部（１１０）を備えている。急速投与部（１１０）は、流入流路（１１１）と、流出流路（１１２）と、流入流路（１１１）と流出流路（１１２）との間に接続され、薬液を貯留する薬液貯留部（１１３）と、薬液貯留部（１１３）への薬液の貯留及び薬液貯留部（１１３）からの薬液の送出を制御する制御部（１１４）とを有している。流入流路（１１１）は、第１の流路（１１１Ａ）と、第１の流路（１１１Ａ）よりも流路断面積が小さい第２の流路（１１１Ｂ）とを有し、制御部（１１４）は、第１の流路（１１１Ａ）を閉止する第１の閉止部（１４１）と、流出流路（１１２）を開閉可能に閉止する第２の閉止部（１４２）とを有している。
