A connection tool is provided with a hollow needle a hub which is provided upon a proximal portion of an outer needle, has a channel in connection within the outer needle, and for which a tube is connectable to the channel from the proximal portion and a valve mechanism for blocking and opening the channel wherein the valve mechanism has a valve body which is provided in the middle of the channel and which has a closable opening portion constructed with elastic material, and an operating member which is supported so as to be movable along the longitudinal direction of the channel for performing opening and closing operations of the opening portion. The connection tool can take a first state in which the opening portion is closed and the operating member is positioned more toward the proximal side than toward the opening portion or a second state in which, when the tubing is connected to the channel from the first state, the operating member is pressed with the tubing so as to move in the tip direction to push open the opening section. The connection tool has a sealing portion for maintaining air-tightness within the channel in the second state.La présente invention se rapporte à un outil de raccord qui est pourvu dune aiguille creuse dun moyeu qui est monté sur une partie proximale dune aiguille externe, qui comprend un canal en liaison avec laiguille externe et pour lequel un tuyau peut être raccordé au canal depuis la partie proximale et dun mécanisme de soupape pour bloquer et ouvrir le canal, le mécanisme de soupape comprenant un corps de soupape qui est agencé au milieu du canal et qui présente une partie ouvrante qui peut être fermée, construite avec un matériau élastique, et un élément de fonctionnement qui est supporté de sorte à être mobile le long de la direction longitudinale du canal pour effectuer des opérations douverture et de fermeture de la partie ouvrante. Loutil de raccord peut avoir un premier état dans lequel la partie ouvrante est fermée et l
