Problem to be solved: to provide a three-way plug which prevents the dead space in which the chemical liquid is retained and prevents the sealing property of the chemical liquid supply path from being damaged.Solution: the three-way Activator 1 is a cylindrical member 3 having a cylindrical outer member 2 and first through third tubes 7 to 9, a cylindrical central member 4 having first and second internal flow paths 20 and 21 positioned within the cylindrical outer member 2, and a cylindrical rotary member capable of rotating between the cylindrical outer member 2 and the cylindrical central member Includes 10.The cylindrical rotary member 10 has first to seventh connecting holes 26 to 28, one end of the first tube 7 and the first internal flow path 20, one end of the second tube 8 and the second internal flow path 21, and one end of the third tube 9 and the other ends of the first and second internal flow paths 20 and 21, respectively, when the rotation angle is at the first angle, which is the same When the rolling angle is the second angle, the first through third connection holes 26 to 28 are closed.Diagram【課題】薬液が滞留するデッドスペースが生じることがなく、かつ薬液供給路の密閉性が損なわれるのを極力防止した三方活栓を提供する。【解決手段】三方活栓1は、円筒状外側部材2及び第1~第3管7~9を有する本体3と、円筒状外側部材2内に位置して第1、第2内部流路20、21を有する円柱状中央部材4と、円筒状外側部材2と円柱状中央部材4との間で回転し得る円筒状回転部材10とを備える。円筒状回転部材10は、その回転角度が第1角度であるときに、第1管7と第1内部流路20の一端、第2管8と第2内部流路21の一端、並びに第3管9と第1、第2内部流路20、21の他端をそれぞれ接続する第1~第3接続孔26~28を有し、該回転角度が第2角度であるときには第1~第3接続孔26~28は閉塞される。【選択図】図4
