PROBLEM TO BE SOLVED: To provide a blood purification device capable of avoiding such a situation in which, a storage bag attached to a hanger part is exchanged carelessly.SOLUTION: A blood purification device comprises holding means 2 capable of holding a storage bag, and uses a liquid in the storage bag for performing blood purification treatment. The holding means 2 comprises: a hanger part 2b capable of moving between a use position where the storage bag is used, and an exchange position where the storage bag is exchanged measuring means g for measuring weight of the storage bag and regulation means 6 for regulating attachment to and detachment from an attachment part 2c of the storage bag. The regulation means 6 is formed of a screening plate capable of moving between a first position for screening the attachment part, and a second position for releasing the attachment part, and the screening plate is attached to the hanger part 2b. Only when the hanger part 2b is at the exchange position, the screening plate can move from the first position to the second position.
