Drive device, lens barrel, image pickup apparatus, lens drive method and method of producing shape memory alloy

A lens barrel, an image pickup apparatus, a lens drive method and a method of producing a shape memory alloy used for the drive device are disclosed. A drive device includes: a lens group for guiding light from a subject; a shape memory alloy adopted to be deformed by an electricity supplied to the shape memory alloy, for moving the lens group in a direction of an optical axis; and electricity-supply controlling means for controlling an amount of the electricity supplied to the shape memory alloy; and a detecting means for detecting whether a movement of the lens group starts or not. In the drive device, a movement amount of the lens group in the direction of the optical axis is controlled based on the amount of electricity supplied when the detecting means detects the movement of the lens group.