An imaging device includes an objective lens that includes a movable lens that is configured so that an in-focus object plane position is changed along with a change in angle of view, an image sensor that acquire an image, a focus control section that implements an autofocus (AF) operation by controlling a position of the movable lens, a reference lens position setting section that sets a reference lens position based on a moving range of the movable lens during a wobbling operation, the wobbling operation being performed every given cycle during the AF operation, and a magnification correction section that performs a magnification correction process that reduces a change in the angle of view of the image due to a change in the position of the movable lens during the wobbling operation relative to the reference lens position.