An automatic focus camera Unit 10, comprises; a piezoelectric element 13a; a driving shaft 13b to be driven by the piezoelectric element 13a; a moving unit 13c to be moved with respect to the driving shaft 13b by a friction force caused by the driving shaft 13b; a microcomputer unit 24 for controlling power supply to the piezoelectric element 13a, and in which the microcomputer unit 24 assumes a preprocessing mode of calculating an amount of adjustment for a power supply time in accordance with a moving direction of the moving unit 13c, and a movement controlling mode of adjusting the supply time and controlling power supply based on the moving direction and the amount of adjustment. In the preprocessing mode, the moving unit 13c is controlled based on the detecting result of the base end sensor 15 and moved in forward and backward directions using the base end position 15a as a reference point, and the amount of adjustment is calculated based on the supply time for which power is supplied while the moving unit 13c is moved in the forward direction and the supply time for which power is supplied while the moving unit 13c is moved in backward direction.