PURPOSE: To provide a semiconductor memory having a small interference between adjacent memory cells and adapted for high integration.

CONSTITUTION: One electrode of a capacitor for forming a memory cell is formed of a semiconductor substrate 17 for forming a sidewall of a trench 18, and an electrode 20 for the capacitor to become the other electrode is formed of a conductor provided in the trench. A transistor for forming the cell is formed of a main surface of the substrate 17 and an insular semiconductor layer 23 formed on a layer insulating film 22 provided on the electrode 20. The layer 23 is so disposed as to be superposed with the electrode 20 of the other electrode of the capacitor. First source/drain region 25 of the transistor formed from a front surface to a rear surface on a part of the layer 23 is electrically connected to the electrode 20 at a rear surface of the region 25.