An image pickup apparatus includes: an optical unit including an incident surface and an emission surface, in which a plurality of optical members are arranged around an optical axis； a polygonal prism image pickup unit including a light receiving surface, a rear surface and a plurality of side faces, in which a plurality of elements including an image pickup device configured to photoelectrically convert light made incident from the optical unit and output an image pickup signal are laminated； and at least one guide, a front portion of which is fixed to the emission surface of the optical unit and a rear portion of which is provided with a plurality of contact surfaces that are respectively in contact with and fixed to the plurality of side faces of the image pickup unit.
