A piezoelectric-element-driven valve includes a valve seat provided on a flow path, a valving element detachably seated on the valve seat, and a piezoelectric element, and is configured to move the valve body by extension of the piezoelectric element. The piezoelectric-element-driven valve also is provided with a detection mechanism for detecting an extension amount of the piezoelectric element, the detection mechanism including a strain sensor, and being capable of detecting an movement amount of the valving element from an output of the strain sensor.