PURPOSE: To promote further integration and enhance electric properties in a semiconductor integrated circuit device having a memory cell of DRAM and reduce the number manufacturing processes in terms of a manufacturing method of the semiconductor integrated circuit device.

CONSTITUTION: In a semiconductor integrated circuit device having a memory cell of DRAM, a silicon oxide film 8, a field plate electrode 7, and a plate electrode 7, a charge accumulation insulation film 8 and an accumulated electrode 10 are buried respectively in a first recess 4 and a second recess 4 which are different in their width and continuous in shape. This construction makes it possible to reduce a plane layout area of a device-to-device isolation region and enhance insulation isolation characteristic. There is no need to install a thermal oxide film between a connection wiring and word line 14. It is, therefore, possible to use manufacturing process of an information accumulation capacity device C which can also serve in the formation of a device isolation region.