An image-capturing device includes a detector which detects that a resistance value of an actuator, made of shape memory alloy, is maintained within a predetermined range. The image-capturing device moves a lens step by step from a place corresponding to a first field in order to obtain image data from each one of the fields provided in a focus region. The image-capturing device also calculates a target place, where the lens should be finally positioned, by using the obtained image data, and then positions the lens at the calculated target place. The foregoing structure allows obtaining reliable and stable data.