A piezoelectric unit includes a piezoelectric element that expands and contracts in a first direction, a drive shaft connected with a first end surface of the piezoelectric element, a weight connected with a second end surface of the piezoelectric element, a protection member covering at least a part of the piezoelectric element, the drive shaft, and the weight, and a movable member engaged with the drive shaft. An inner wall surface of the protection member includes a weight position regulating portion that regulates a position of the weight, an element position regulating portion that regulates a position of the piezoelectric element, and a shaft position regulating portion that regulates a position of the drive shaft. An outer wall surface of the protection member has a movable member regulating portion that prevents the movable member from approaching the piezoelectric element.