This invention provides a technique capable of always keeping digital watermark information embedded in image data having the embedded digital watermark information by an optimum scheme on the basis of a time factor, or removing a digital watermark, or erasing the image data. The solid state imaging device of the present invention includes a vertical overflow function and has a feature in which potential of a semiconductor substrate is changed from a high potential to a low potential in a stepwise manner during a period from an exposure start to an exposure end. A collar is fastened to a nipple to the first end of the upper chamber.