Blood purification device

A blood purification device includes a chamber, a liquid feed line, an air introduction unit, a liquid level adjustment unit, and a control unit. The chamber is provided on a blood circuit for extracorporeally circulating patient's blood and introduces purified plasma obtained by purifying plasma separated by a plasma separator provided on the blood circuit, or a replenishing liquid for replenishing the plasma separated by the plasma separator, into the blood circuit. The liquid feed line is capable of sending the purified plasma or the replenishing liquid to the chamber. The air introduction unit is capable of introducing air into the liquid feed line. The liquid level adjustment unit is capable of adjusting a liquid level height in the chamber. At the end of blood purification treatment, the control unit performs a liquid recovery process for sending the purified plasma or the replenishing liquid to the chamber via the liquid feed line while introducing air into the liquid feed line by the air introduction unit and maintains the liquid level height in the chamber at a predetermined liquid level height by the liquid level adjustment unit.