1. An imaging device comprising: an imaging optical system operable to form an optical image of an object; an image sensor operable to take the optical image of the object and to convert the optical image to an electric image signal; a feature point extraction section operable to extract a feature point of the object based on the generated electric image signal; and a display section operable to display an image based on the generated electric image signal and an area frame indicating a position of the feature point in a manner that the area frame is overlaid onto the image when displayed, wherein the display section displays the area frame so that a high frequency component of a time-series oscillation of a positional movement of the area frame is smaller than a high frequency component of a time-series oscillation of a positional movement of the same feature point on the display section.