ACTUATOR

PROBLEM TO BE SOLVED: To provide an actuator which allows a moving body to smoothly slide on an outer peripheral surface of a driving shaft even if an adhesive is adhered to the outer peripheral surface of the driving shaft on which the moving body slides during assembling a piezoelectric element, the driving shaft, and a holding member.SOLUTION: An actuator includes a piezoelectric element 2 which is an electromechanical conversion element, a driving shaft 3, a moving body 5 sliding on an outer peripheral surface of the driving shaft 3, and a holding member 5 holding the driving shaft 3 through an adhesive. A pressed part 6, which is pressed by a first pressing member 115 provided at an assembly jig 110 which is used for assembling the holding member 5 and the driving shaft 3, is provided on the outer peripheral surface of the driving shaft 3. The pressed part 6 is formed so that at least a contact part 61 contacting with the first pressed member 115 and a contact part surrounding area 62 are recessed from a fourth outer peripheral surface 34 of the driving shaft 3 in which the pressed part 6 is provided.