An image-capturing device including: an imaging optical system which is configured to capture an optical image of a subject; an imaging optical system retaining member which retains the imaging optical system; an imaging element which is configured to convert the optical image into an electrical signal; a substrate which is arranged on a back side of the imaging optical system retaining member and retains the imaging element; and a plurality of substrate joint pieces each of which extends from the imaging optical system retaining member toward the substrate, wherein tip parts of the plurality of substrate joint pieces on a substrate side and the substrate are joined by an indirect bond structure using at least one joint intermediate member which is adhered to at least one of the tip parts of the plurality of substrate joint pieces and the substrate with an adhesive, and a fixation structure.