A semiconductor memory device includes a memory cell capacitor for storing information, wherein the memory cell capacitor includes a capacitor insulation film of a double oxide on a lower electrode. The lower electrode has a layered structure of Ir/IrO.sub.2 /Ir or Ru/RuO.sub.2 /Ru acting as a diffusion barrier of oxygen or Pb. Further, the use of a Pt--Ir alloy is disclosed for the lower electrode.