A linear ultrasonic motor includes a vibrator having a piezoelectric element, a movable part applying a pressing force to the vibrator and bringing the vibrator into pressed contact with a base part, a cover part being fixed to the base part, a rolling part being rollably held between a movable guide part of the movable part and a cover guide part of the cover part, and a body to be driven having a transmission member that is pivotably supported and able to move only in the movable direction. The transmission member includes a bias part that abuts on a transmission part of the movable part and applies a biasing force of biasing the movable part to the rolling part to the transmission part. The rolling part is held by a resultant force of the pressing force or a reaction force of the pressing force, and the biasing force.