A photoreception device (1; 1A-D) comprising: a substrate; a photoreceptor element including a photoreceptor portion upon an upper surface thereof and a lower surface thereof is mounted upon the substrate; and an insulating resin mass (30; 30A-B) that contains a flat upper surface and an opening (31; 31A-B) that exposes the photoreceptor portion of the photoreceptor element, that is formed upon the substrate to be thicker than thickness of the photoreceptor element, and that adheres closely against side surfaces of the photoreceptor element, the side surfaces surrounding the photoreceptor element; wherein: the insulating resin mass contains a step portion (32; 32A-B) that is provided to a height between the flat upper surface thereof and the upper surface of the photoreceptor portion; the insulating resin mass is formed to be thicker than the thickness of the photoreceptor element at positions where the step portion is provided; the step portion extends parallel to at least one pair of mutually opposed side surfaces of the photoreceptor element, at a periphery of the opening; the step portion is formed at an intersection portion of the insulating resin mass with the upper surface of the photoreceptor element; a thickness of the insulating resin mass gradually decreases toward the upper surface of the photoreceptor element at the step portion of the insulating resin mass; and a thickness of a portion where the insulating resin mass closely adheres to the side surfaces surrounding the photoreceptor element is substantially equal to or thicker than the thickness of the photoreceptor element. a substrate; a photoreceptor element including a photoreceptor portion upon an upper surface thereof and a lower surface thereof is mounted upon the substrate; and an insulating resin mass (30; 30A-B) that contains a flat upper surface and an opening (31; 31A-B) that exposes the photoreceptor portion of the photoreceptor element, that is formed upon the substrate to be thicker than thickness of the photoreceptor element, and that adheres closely against side surfaces of the photoreceptor element, the side surfaces surrounding the photoreceptor element; wherein: the insulating resin mass contains a step portion (32; 32A-B) that is provided to a height between the flat upper surface thereof and the upper surface of the photoreceptor portion; the insulating resin mass is formed to be thicker than the thickness of the photoreceptor element at positions where the step portion is provided; the step portion extends parallel to at least one pair of mutually opposed side surfaces of the photoreceptor element, at a periphery of the opening; the step portion is formed at an intersection portion of the insulating resin mass with the upper surface of the photoreceptor element; a thickness of the insulating resin mass gradually decreases toward the upper surface of the photoreceptor element at the step portion of the insulating resin mass; and a thickness of a portion where the insulating resin mass closely adheres to the side surfaces surrounding the photoreceptor element is substantially equal to or thicker than the thickness of the photoreceptor element. the insulating resin mass contains a step portion (32; 32A-B) that is provided to a height between the flat upper surface thereof and the upper surface of the photoreceptor portion; the insulating resin mass is formed to be thicker than the thickness of the photoreceptor element at positions where the step portion is provided; the step portion extends parallel to at least one pair of mutually opposed side surfaces of the photoreceptor element, at a periphery of the opening; the step portion is formed at an intersection portion of the insulating resin mass with the upper surface of the photoreceptor element; a thickness of the insulating resin mass gradually decreases toward the upper surface of the photoreceptor element at the step portion of the insulating resin mass; and a thickness of a portion where the insulating resin mass closely adheres to the side surfaces surrounding the photoreceptor element is substantially equal to or thicker than the thickness of the photoreceptor element.