PROBLEM TO BE SOLVED: To provide a dialyzer and a control method capable of performing water removal corresponding to body weight at a preset water removal rate regardless of an embodiment of fluid replenishment.SOLUTION: A dialyzer 100 comprises: a blood circuit 110； blood purification means 120； a dialysate circuit 130 including a dialysate feeding unit 133 for feeding dialysate so that fluid replenishment is performed by water removal or reverse filtration via the blood purification means 120； and a control unit 140 for controlling the dialysate feeding unit 133 so as to perform water removal from the blood circuit 110 and intermittent fluid replenishment to the blood circuit 110. The dialyzer calculates a time for performing fluid replenishment on the basis of a predetermined fluid replenishment amount and a predetermined fluid replenishment rate r； in a period in which the fluid replenishment is not performed, performs water removal corresponding to body weight at a set water removal rate f1 as well as performs water removal corresponding to replenisher recovery at a replenisher recovery rate f2 based on the predetermined fluid replenishment amount； and in a period in which the fluid replenishment is being performed, performs the fluid replenishment at a reverse filtration rate R calculated by subtracting the set water removal rate f1 from the predetermined fluid replenishment rate r.SELECTED DRAWING: Figure 4COPYRIGHT: (C)2020,JPO&INPIT【課題】補液の実施態様によらず、予め設定された除水速度で体重分の除水を行うことが可能な透析装置及び制御方法を提供する。【解決手段】透析装置１００は、血液回路１１０と、血液浄化手段１２０と、血液浄化手段１２０を介して除水又は逆濾過による補液を行うように透析液を送る透析液送液部１３３を有する透析液回路１３０と、血液回路１１０からの除水及び血液回路１１０への間歇的な補液を実施するように透析液送液部１３３を制御する制御部１４０と、を備え、所定の補液量及び所定の補液速度ｒに基づいて補液を実施する時間を算出し、補液実施中以外は、設定除水速度ｆ１で体重分の除水を行うと共に、所定の補液量に基づいた補液回収速度ｆ２で補液回収分の除水を行い、補液実施中は、所定の補液速度ｒから設定除水速度ｆ１を減じて算出した逆濾過速度Ｒで補液を行う。【選択図】図４
