Abstract: A semiconductor device includes a semiconductor substrate having a major surface; a first interlayer insulating film formed on the semiconductor substrate and having an opening defined therein so as to open at the major surface of the semiconductor substrate; a connecting member made of Si as a principal component and embedded in the opening; a lower capacitor electrode connected electrically with the major surface of the semiconductor substrate through the connecting member; a capacitor dielectric film formed on the lower capacitor electrode; an upper capacitor electrode formed on the capacitor dielectric film; and a second interlayer insulating film formed on the capacitor upper electrode. The lower capacitor electrode referred to above is made of a principal component selected from the group consisting of ruthenium and iridium and contains oxygen in a quantity of 0.001 to 0.1% by atom and/or at least one impurity element in a quantity of 0.1 to 5% by atom.