Abstract: An exemplary embodiment illustrates a zener diode structure, wherein the zener diode structure includes a first-type semiconductor layer, a second-type semiconductor layer, a first electrode, a second electrode, and an insulation layer. The second-type semiconductor layer is disposed in a designated area in the first-type semiconductor layer. The first electrode is disposed on the bottom side of the first-type semiconductor layer. The second electrode is disposed above the first-type and the second-type semiconductor layers in corresponding to the central area of the second-type semiconductor layer. The insulation layer is disposed above the first-type and the second-type semiconductor layers surrounding the second electrode. The disclosed zener structure having the insulation layer can reduce the short circuit issue resulting from overflow of an adhesive material during the zener diode packaging process.