According to this invention, a semiconductor device has an upper surface on which an external connection electrode is formed and a lower surface which opposes the upper surface and is in a mirror surface state. A roughened region roughened by laser marking is formed at part of the lower surface. The roughened region includes a product information mark of the semiconductor device itself. The product information mark is printed by laser marking. The number, size, shape, and layout position of the roughened regions are decided to make it possible to, when the lower surface is irradiated with light, read the product information from the difference in light reflectance between the roughened region and mirror-finished region.