The etch-back amount of a silicon oxide film of a memory array which is a higher altitude portion is increased when etching back and flattening the silicon oxide film by arranging a first-layer wiring on a BPSG film covering an upper electrode of an information-storing capacitative element only in a peripheral circuit but not arranging it in the memory array. Thus, a DRAM having a stacked capacitor structure is obtained such that the level difference between the memory array and peripheral circuit is decreased, and the formation of wiring and connection holes are easy.