A power semiconductor device includes: a substrate; 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; an NISO region disposed in a lower portion of the well region inside the substrate, and having a first n-type impurity concentration; and 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.