A power semiconductor device includes a substrate including a first epitaxial layer, a second epitaxial layer, and a base substrate where the first epitaxial layer is disposed between the second epitaxial layer and the base substrate. The power semiconductor device includes an anode electrode and a cathode electrode disposed on the substrate, a well region disposed inside the substrate in a lower portion of the anode electrode, and having p-type conductivity. The power semiconductor device includes an NISO region disposed in a lower portion of the well region inside the substrate, and having a first n-type impurity concentration. The power semiconductor device includes an n-type buried layer disposed in a lower portion of the NISO region, and having a second impurity concentration greater than the first n-type impurity concentration, inside the substrate.