PROBLEM TO BE SOLVED: To provide a valve unit for artificial dialyzer which eliminates the need for using two kinds of valve units, satisfying the requirements for the artificial dialyzer with one kind of valve unit.SOLUTION: A valve unit 1 for artificial dialyzer comprises: a first valve 12 and a second valve 13 communicating with one chamber of a first chamber unit 16 with a pair of chambers and a third valve 14 and a fourth valve 15 communicating with one chamber of a second chamber unit 17 with a pair of chambers. In the valve unit 1: the first valve 12, the second valve 13, the third valve 14, and the fourth valve 15 are arranged counterclockwise in this order in a cross-in-square shape a first joint 23 to communicate an output side of the first valve 12 with the one chamber of the first chamber unit 16 is a swingable-type movable joint and a second joint 25 to communicate an output side of the fourth valve 15 with the one chamber of the second chamber unit 17 is a swingable-type movable joint.
