Problem to be solved: to provide a chemical liquid circuit capable of preventing the backflow of the blood more reliably and more easily attaching it to the infusion apparatus.Chemical circuit 500 isThe first base line 508 in which the first chemical liquid flowsThe second base line 509 flowing through the second chemical fluidThe subject line 503 connected to the first baseline 508 and the second baseline 509A first closed portion 100A having a first closing mechanism 120a closing an internal flow path is provided.The first closing mechanismA first moving member 122a1 and a second moving member 122a2 each having a flow pathThe first movable member 122a and the second movable member 122a2 are slidably received by a first housing 124a.After opening the flow path of the first moving memberThe second moving member 122a2 is configured to open the flow path.血液の逆流をより確実に防止でき且つより容易に注入装置に装着可能である薬液回路を提供する。薬液回路５００は、第１薬液が流れる第１ベースライン５０８と、第２薬液が流れる第２ベースライン５０９と、第１ベースライン５０８及び第２ベースライン５０９に接続される被験者ライン５０３と、内部流路を閉鎖する第１閉鎖機構１２０ａを有する第１閉鎖部１００ａとを備え、第１閉鎖機構１２０ａは、それぞれ流路を有する第１移動部材１２２ａ１及び第２移動部材１２２ａ２と、第１移動部材１２２ａ１及び第２移動部材１２２ａ２を摺動可能に収容する第１ハウジング１２４ａとを備えており、第１移動部材１２２ａ１の流路を開放した後に、第２移動部材１２２ａ２の流路が開放されるように構成されている。
