In an auto image stabilization system, a driving member formed as a wire of shape memory alloy (SMA) is retained by a projection of an image capturing unit. A distance Lb from the rotation center of an elastic deforming part to center of gravity (point of application) of the image capturing unit is longer than a distance La from the rotation center of the elastic deforming part to the projection (power point). In the configuration, equivalent mass (apparent mass) of the image capturing unit becomes (Lb/La) times, and it causes deterioration in response. Consequently, the driving member having an ellipse-shaped section in which a value obtained by dividing the width in the longer direction of the section by the width in the shorter direction is 1.3 or larger is employed. As a result, heat dissipation of the driving member increases, so that response in the SMA actuator can be properly improved.