[Problem] To provide a dialysate extraction device configured so that the cleanliness of an extraction opening can be reliably maintained when connecting a connection means to the extraction opening.[Solution] A dialysate extraction device is provided with: a dialysate extraction means (9) having an extraction opening (12) which is formed in a protruding manner and through which liquid can be extracted； a cylindrical outer peripheral wall section (13) formed in the dialysate extraction means (9) and covering the outer periphery of the extraction opening (12)； a connection means (15) having formed thereon both a connection section (15aa) which is connected to the extraction opening (12) and a seal member (16) which fits to the inner peripheral surface of the outer peripheral wall section (13) and allowing liquid to be extracted from the extraction opening (12) while being connected at the connection section (15aa)； and tapered sections (13d, 13e) formed on the inner peripheral surface of the outer peripheral wall section (13) and correcting, in the process of insertion of the connection means (15) into the outer peripheral wall section (13) and before the front end (15c) of the connection means (15) reaches the protrusion end (12a) of the extraction opening (12), the position and attitude of the connection means (15) relative to the extraction opening (12).Cette invention concerne un dispositif d'extraction d'un dialysat conçu pour maintenir avec fiabilité la propreté de l'ouverture d'extraction lors de son raccord avec le système de connexion.Le dispositif d'extraction du dialysat comprend les éléments suivants : un système d'extraction du dialysat (9) comportant une ouverture d'extraction (12) qui forme une protubérance et par laquelle le liquide est extrait ； une section de paroi périphérique externe cylindrique (13) formée dans le système d'extraction du dialysat (9) et recouvrant la périphérie externe de l'ouverture d'extraction (12) ； un système de connexio
