A fitting structure for fitting a piezoelectric element to an actuator base that includes an opening that formed in the actuator base and accommodates the piezoelectric element, a receiver that inwardly protrudes from an inner circumferential edge of the opening and receives the piezoelectric element, a hole defined by an inner end of the receiver and communicates with the opening, a protrusion that protrudes from the inner end of the receiver onto the hole and faces the piezoelectric element through the hole, an adhesive part filled in a space defined by the piezoelectric element, the inner circumferential edge, and the receiver and is solidified in the space to adhere the piezoelectric element to the inner circumferential edge and the receiver, and a stopper formed on one of the receiver and protrusion and stops a capillary phenomenon of the adhesive between the piezoelectric element and the receiver and protrusion.