This invention is a pressure control valve unit including: a unit substrate; a first valve chamber provided at one side of the unit substrate, forming a part of a first liquid flow-path; a second valve chamber provided at the other side of the unit substrate, forming a part of a second liquid flow-path; a first opening-closing valve provided in the first valve chamber; and a second opening-closing valve provided in the second valve chamber. The first liquid flow-path and the second liquid flow-path are formed independently of each other. A pressure of a liquid flowing in the first liquid flow-path and a pressure of a liquid flowing in the second liquid flow-path can be controlled at respective predetermined pressures independently of each other.