PROBLEM TO BE SOLVED: To accurately measure an amount of removed water.SOLUTION: A blood purifying device includes: a blood purifier 120 at least one of a dialysis fluid storage part 140 and a replenishment fluid storage part 150 an exhaust fluid storage part 137 a first support member 180 including a first cam follower 184 for supporting the at least one of the dialysis fluid storage part 140 and the replenishment fluid storage part 150 a second support member 191 including a second cam follower 192 for supporting the exhaust fluid storage part 137 a cam shaft 171 including a first cam 172 that comes in contact with the first cam follower 184, and a second cam 173 that comes in contact with the second cam follower 192 and a scale 139 arranged so as to support each of the first support member 180 and the second support member 191.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2017,JPO&INPIT【課題】除水量を正確に測定する。【解決手段】血液浄化器120と、透析液貯液部140および補液貯液部150の少なくとも一方と、排液貯液部137と、透析液貯液部140および補液貯液部150の少なくとも一方を支持し、第1カムフォロア184を含む第1支持部材180と、排液貯液部137を支持し、第2カムフォロア192を含む第2支持部材191と、第1カムフォロア184と接する第1カム172、および、第2カムフォロア192と接する第2カム173を含むカムシャフト171と、第1支持部材180および第2支持部材191の各々を支持可能に配置された秤139とを備える。【選択図】図1