Abstract: A sole state imaging device includes a photodetection diode and an insulated gate field effect transistor provided adjacent to the photodetection diode for optical signal detection. In a method of making the device, a carrier pocket is formed in a second well region, and an element isolation insulating film is formed to isolate adjacent unit pixels from each other. In addition, an element isolation region of an opposite conductivity type is formed to isolate a second semiconductor layer of one conductivity type in such a way as to include the lower surface of the element isolation insulating film and reach a first semiconductor layer.