In one embodiment of the present invention, provided is a blood separating device comprising: a first kit which comprises a first space for receiving blood on the inside thereof, and wherein the first space is separated between top and bottom by means of a first opening part a second kit which comprises a second space for receiving blood on the inside thereof, and wherein the second space is separated between top and bottom by means of a second opening part a plate which is disposed between the first kit and the second kit, and is provided with a through-connection hole for establishing fluid through connection of the first space and the second space a stopper having a first bar which is provided projecting upwards from the plate and opens and closes the first opening part, and a second bar which is provided projecting downwards from the plate and opens and closes the second opening part a first cap which covers the upper end part of the first kit and a second cap which covers the bottom end part of the second kit. The stopper allows blood to be separated a plurality of times by respectively opening and closing the first opening part and the second opening part.Selon lun de ses modes de réalisation, la présente invention concerne un dispositif de séparation du sang comprenant : un premier ensemble qui comprend un premier espace pour recevoir du sang à lintérieur de celui-ci, le premier espace étant séparé entre une partie supérieure et une partie inférieure au moyen dune première partie douverture un second ensemble qui comprend un second espace pour recevoir du sang à lintérieur de celui-ci, le second espace étant séparé entre une partie supérieure et une partie inférieure au moyen dune seconde partie douverture une plaque qui est disposée entre le premier ensemble et le second ensemble et qui comporte un trou de raccordement traversant pour établir une liaison traversante de fluide du premier espace et du second espace un bouchon ayant une première barre qui es
