To provide a semiconductor device and its manufacturing method that can suppress both leakage currents resulting from thermal emission of electrons from an electrode and from the tunneling effect, which has an MIM capacitor capable to maintain a high specific inductive capacity. The semiconductor device is equipped with a capacitor that is formed by laminating a lower electrode 16, a capacitance insulating film 18, and an upper electrode 20 one after another, wherein the capacitance insulating film 18 is composed of Hf oxide or Zr oxide, and a barrier film 17 is formed between the lower electrode 16 and the capacitance insulating film 18 that is composed of Hf oxide or Zr oxide containing at least either one of Al and Si. |