PROBLEM TO BE SOLVED: To provide a blood purification device capable of improving purification efficiency of dialysate, and suppressing lowering of electrolyte included in the dialysate and necessary for treatment.SOLUTION: The blood purification device includes: storage means 6 capable of storing a prescribed amount of dialysate necessary for blood purification treatment； a dialysate circulation line (a dialysate introduction line L1 and a dialysate discharge line L2) capable of circulating the dialysate by introducing the dialysate of the storage means 6 to a dialyzer 1, and discharging effluent from the dialyzer 1 to the storage means 6； and dialysate purification means 7 for purifying the dialysate in the dialysate circulation line. The blood purification device can be changed over between a treatment state where the dialysate can be introduced to the dialyzer 1 without mediating the dialysate purification means 7, and a purification state where the dialysate can be purified by the dialysate purification means 7. After the treatment state is started, on the condition that a prescribed condition is satisfied, the blood purification device is changed into the purification state.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2018,JPO&INPIT【課題】透析液の浄化効率を向上させることができるとともに、透析液に含まれる治療に必要な電解質の低下を抑制することができる血液浄化装置を提供する。【解決手段】血液浄化治療で必要とされる所定量の透析液を収容可能な収容手段６と、収容手段６の透析液をダイアライザ１に導入しつつ当該ダイアライザ１からの排液を収容手段６に排出して透析液を循環させ得る透析液循環ライン（透析液導入ラインＬ１及び透析液排出ラインＬ２）と、透析液循環ラインの透析液を浄化する透析液浄化手段７とを具備した血液浄化装置であって、透析液を透析液浄化手段７を介さずにダイアライザ１に導入可能な治療状態と、透析液を透析液浄化手段７にて浄化可能な浄化状態とが切替可能とされるとともに、治療状態開始後、所定条件を満たしたことを条件として、浄化状態に切り替えられるものである。【選択図】図１
