PURPOSE: To improve the picture quality by reduction of blooming by a method wherein the thickness of a well layer on the side of photo diode is reduced on the side of vertical CCD shift register.

CONSTITUTION: The flat well layer 10'-1 W2 deep is formed on a semiconductor substrate 11, and further an insulation oxide film 13 for picture element isolation is formed. Next, a low concentration diffused layer 9 for a buried channel is formed, and electrodes 8-1 and 8-2 constituting the CCD electrode are formed. Then, a hole 14-1 is bored in part of the region corresponding to the photo diode. Finally, a photo diode diffused layer 1'-1 is formed.