A device for measuring distances to multiple subjects includes an imaging optical system, a pupil orientation sensor having multiple pixels including photoelectric conversion elements arranged two-dimensionally, the pupil orientation sensor selectively receiving a light flux passed through any of the multiple regions, an image acquisition device configured to simultaneously acquire each of multiple images corresponding to the multiple regions from the pupil orientation sensor, a focusing control device configured to independently drive the physically-separated multiple lenses of the imaging optical system on the basis of the multiple images acquired by the image acquisition device to control the lenses to be focused on multiple subjects each having a different focusing distance, and a first calculation device configured to calculate each of the focusing distances to the multiple subjects respectively subjected to focusing control by the focusing control device.