The actuator includes a vibration plate including a fixing portion for fixing the vibration plate to a holding member, and a connection portion for connecting a center portion and the fixing portion, and is provided between a surface and a friction-sliding surface in a direction in which the vibration plate is pressed against the rotor by a pressurizing force produced by a pressure member. When finishing a surface on which a piezoelectric device is to be fixed to the vibration plate to a uniform surface by polishing, a decrease in the performance of the ultrasonic motor due to deformation of the vibration plate that is caused by warping of support portions that extend from both ends thereof or by burrs or the like can be prevented, and the time required to polish the vibration plate can be reduced.