1. An imaging apparatus comprising: an image sensor configured to photoelectrically convert an image of an object formed by an imaging lens to generate an image signal; a foreign substance information detection unit configured to detect foreign substance information including at least information about a position of a foreign substance adhered to an optical element disposed in front of the image sensor; a determination unit configured to determine whether the position of the foreign substance detected by the foreign substance information detection unit overlaps a predetermined area of the object by analyzing the image signal of the object generated by the image sensor; and a changing unit configured to change a relative position of the image of the object formed on the image sensor and the image sensor when the determination unit determines that the position of the foreign substance overlaps the predetermined area.