A pressure regulating valve for an inkjet printer includes a negative pressure generator including a negative pressure chamber, a pressure receiving member, and a pressure device. A sealing valve includes a pressure chamber, a valve element, and a valve element pressing device. A linkage mechanism includes a communication flow chamber and an operating lever swingably provided in the communication flow chamber and including an arm section, a first engagement section, and a second engagement section. A first length of the arm section is greater than a second length of the arm section. The first engagement section is pressed against the pressure receiving member to swing the operating lever and the second engagement section moves the valve element to open the sealing valve when the pressure receiving member is moved inwardly with respect to the negative pressure chamber against a force applied by the pressure device.