A blood purification apparatus comprising: a peristaltic pump that includes a stator to which a pump tube including a first portion and a second portion is detachably attached, and a rotor including a roller (Ra) and a guide portion, the roller (Ra) delivering liquid by squeezing the pump tube attached to the stator, the guide portion retaining the pump tube at an appropriate position where the pump tube is squeezable with the roller (Ra), the rotor being rotatable about a predetermined axis; an anchor member that anchors an attaching member to which the pump tube is attached; and a displacing portion that displaces the attaching member between a set position and an unset position by moving the anchor member with the attaching member being anchored by the anchor member, wherein an attachable state in which the first portion of the pump tube rests at the appropriate position is established when the anchor member is moved from the unset position to the set position with the guide portion of the peristaltic pump being stopped in a specific phase, and loading in which the guide portion draws the pump tube into the stator such that the first portion and the second portion of the pump tube rest at the appropriate position is executed when the peristaltic pump is activated in the attachable state such that the rotor is rotated by a predetermined angle, and/or a detachable state in which the first portion of the pump tube rests at an inappropriate position deviating from the appropriate position is established when the anchor member is moved from the set position to the unset position with the guide portion of the peristaltic pump being stopped in a specific phase, and unloading in which the guide portion pushes the pump tube out of the stator such that the first portion and the second portion of the pump tube rest at the inappropriate position is executed when the peristaltic pump is activated in the detachable state such that the rotor is rotated by a predetermined angle, characterized in that the peristaltic pump is one of a plurality of peristaltic pumps, the pump tube is one of a plurality of pump tubes attached to the attaching member, a number of the plurality of pump tubes is equal to a number of the plurality of peristaltic pumps, and the plurality of pump tubes are loaded or unloaded by moving the anchor member between the set position and the unset position. a peristaltic pump that includes a stator to which a pump tube including a first portion and a second portion is detachably attached, and a rotor including a roller (Ra) and a guide portion, the roller (Ra) delivering liquid by squeezing the pump tube attached to the stator, the guide portion retaining the pump tube at an appropriate position where the pump tube is squeezable with the roller (Ra), the rotor being rotatable about a predetermined axis; an anchor member that anchors an attaching member to which the pump tube is attached; and a displacing portion that displaces the attaching member between a set position and an unset position by moving the anchor member with the attaching member being anchored by the anchor member, wherein an attachable state in which the first portion of the pump tube rests at the appropriate position is established when the anchor member is moved from the unset position to the set position with the guide portion of the peristaltic pump being stopped in a specific phase, and loading in which the guide portion draws the pump tube into the stator such that the first portion and the second portion of the pump tube rest at the appropriate position is executed when the peristaltic pump is activated in the attachable state such that the rotor is rotated by a predetermined angle, and/or a detachable state in which the first portion of the pump tube rests at an inappropriate position deviating from the appropriate position is established when the anchor member is moved from the set position to the unset position with the guide portion of the peristaltic pump being stopped in a specific phase, and unloading in which the guide portion pushes the pump tube out of the stator such that the first portion and the second portion of the pump tube rest at the inappropriate position is executed when the peristaltic pump is activated in the detachable state such that the rotor is rotated by a predetermined angle, characterized in that the peristaltic pump is one of a plurality of peristaltic pumps, the pump tube is one of a plurality of pump tubes attached to the attaching member, a number of the plurality of pump tubes is equal to a number of the plurality of peristaltic pumps, and the plurality of pump tubes are loaded or unloaded by moving the anchor member between the set position and the unset position.