<；P>；PROBLEM TO BE SOLVED: To provide a vessel for preparing blood components, which is capable of accurately collecting a prescribed quantity of blood. <；P>；SOLUTION: The vessel for preparing blood components includes a vertically long outer barrel 11 which has a fluid intake port 21 for introducing a fluid such as blood, a component outlet 22 for extracting part of components of the fluid formed at one end and a ventilation part 30 with a ventilation filter 31 formed at the other end； a slidably disposed partition member 12 which has a sealed part on the whole inner surface of the outer barrel 11； a first magnetic member 13 disposed integrally with the partition member 12 or connected to the partition member 12； and a second magnetic member 14 close to the outer surface of the outer barrel 11 and disposed movably in the longitudinal direction of the outer barrel 11. The partition member 12 is slid with the magnetic force working between the first magnetic member 13 and the second magnetic member 14. <；P>；COPYRIGHT: (C)2009,JPO&INPIT
