PURPOSE: To greatly enlarge charge storage capacity of a charge-coupled device without allowing its area to increase in the direction of its surface by a method wherein junction capacity is made use of along the junction between a storage auxiliary layer and a charge storage layer surrounding the storage auxiliary layer.

CONSTITUTION: A P-type storage auxiliary layer 31 is provided in an N-type charge storage layer 25. The upper and lower surfaces of the storage auxiliary layer 31 in the direction of its thickness and its left end are in contact with the charge storage layer 25. The right end of the storage auxiliary layer 31 is in contact with an inter-element isolating layer 29. Further, the overall vertical width of the storage auxiliary layer 31 is equivalent to that of the charge storage layer 25. It follows therefore that the two edges of the storage auxiliary layer 31 are in contact with an impurity region 22, which results in the establishment of electrical connection between the storage auxiliary layer 31 and impurity region 22.