A pressure-regulating valve in which the pressure of a functional liquid fed to a primary chamber from a functional liquid feeding means is regulated by opening and closing a valve body, the functional liquid is fed to a secondary chamber, and the functional liquid is fed from the secondary chamber to an inkjet-type functional droplet ejection head; wherein the valve body has a valve body main body that directly opens and closes with respect to a valve seat, the valve body main body being provided to the primary chamber; and a valve holder including a holding part that holds the valve body main body and an actuating shaft that comes in contact with a pressure-receiving membrane, the actuating shaft extending concentrically through the communication flow passage from the holding part; the actuating shaft is formed so as to taper to a point toward the pressure-receiving membrane; and the communication flow passage is formed to have a complementary shape with respect to the actuating shaft.