The invention provides a semiconductor device that solves a problem of reflection of a pattern of a wiring formed on a back surface of a semiconductor substrate on an output image. A reflection layer is formed between a light receiving element and a wiring layer, that reflects an infrared ray toward a light receiving element the without transmitting it to the wiring layer, the infrared ray entering from a light transparent substrate toward the wiring layer through a semiconductor substrate. The reflection layer is formed at least in a region under the light receiving element uniformly or only under the light receiving element. Alternatively, an anti-reflection layer having a function of absorbing the entering infrared ray to prevent transmission thereof may be formed instead of the reflection layer.