An actuator including two or more detection targets disposed on a surface and another surface of a lens barrel, respectively, an oscillating unit including a first oscillation circuit unit including two or more oscillation circuits disposed to face the surface and a second oscillation circuit unit including two or more oscillation circuits disposed to face the other surface to output oscillation signals, and a determining unit to calculate a position of the lens barrel from the oscillation signals output from the oscillating unit. A frequency range of an oscillation signal output from any one of the two or more oscillation circuits of the first oscillation circuit unit is different from that of an oscillation signal output from any one of the two or more oscillation circuits of the second oscillation circuit unit.