A solid-state imaging device is formed on a silicon substrate for providing a MOS type solid-state imaging device which has a device isolation structure and causes a small amount of leak current. The solid-state imaging device includes, for each pixel, an imaging region which includes a photodiode having a charge accumulation region of a first conductivity type, a transistor and a device isolation region whose depth is less than a depth of the charge accumulation region of the first conductivity type, at which an impurity density is at maximum.