An imaging apparatus having a light receiving element having a micro lens array provided with a plurality of micro lenses, and a plurality of photoelectric conversion elements, and outputting a light receiving signal obtained by receiving a light beam from an optical system via the micro lens array; a detector that detects shift amounts of image plane by the optical system respectively for a plurality of focus detecting positions set at a plurality of positions in the image plane by the optical system; and a controller that determines a focus adjusting position for the optical system based on a plurality of the shift amounts detected respectively for the plurality of focus detecting positions and a range of the image plane where an image based on the light receiving signal is enabled to be produced, and obtains the light receiving signal at the focus adjusting position with the light receiving element.