A semiconductor device (100, 200, 300, 400, 500, 600) comprising: a semiconductor substrate comprising a layer having a first conductivity type, a first wiring layer, and a second wiring layer; an electronic component mounted on the substrate, a first electrode of the electronic component; a second electrode of the electronic component; a first bump between the first electrode and the first wiring layer; and a second bump between the second electrode and the second wiring layer; wherein the substrate comprises a Zener diode formed by an impurity diffusion region having a second conductivity type opposite to the first conductivity type and the layer having the first conductivity type, the impurity diffusion region being formed in the layer having the first conductivity type, the Zener diode being electrically connected in parallel with the electronic component; a plurality of penetration electrodes which are electrically connected to the electronic component and formed in respective holes in the semiconductor substrate, the plurality of penetration electrodes including a first penetration electrode and a second penetration electrode which penetrate the semiconductor substrate between an upper surface and a lower surface of the semiconductor substrate; the first wiring layer is formed on the upper surface of the semiconductor substrate and is electrically connected to an upper edge of the first penetration electrode, and connects the impurity diffusion region of the Zener diode to the first penetration electrode and the first electrode of the electronic component; the second wiring layer is formed on the upper surface of the semiconductor substrate and is electrically connected to an upper edge of the second penetration electrode, and connects the layer having the first conductivity type of the Zener diode to the second penetration electrode and the second electrode of the electronic component; and a protection film (208, 222) comprising a nitride film formed on the upper surface of the semiconductor substrate for protecting the impurity diffusion region at the upper surface, and an insulating oxide film formed on the inner wall of the holes in the semiconductor substrate and on the lower surface of the semiconductor substrate; wherein the first wiring layer is connected to the impurity diffusion region of the Zener diode via a first connecting portion, wherein the first connecting portion is formed in an opening in the nitride film, wherein the second wiring layer is connected to the layer having the first conductivity type of the Zener diode via a second connecting portion, wherein the second connecting portion is formed in an opening in the nitride film, and wherein the Zener diode is adapted to avoid, in use, that a voltage higher or equal to a predetermined voltage is applied to the electronic component. a semiconductor substrate comprising a layer having a first conductivity type, a first wiring layer, and a second wiring layer; an electronic component mounted on the substrate, a first electrode of the electronic component; a second electrode of the electronic component; a first bump between the first electrode and the first wiring layer; and a second bump between the second electrode and the second wiring layer; wherein the substrate comprises a Zener diode formed by an impurity diffusion region having a second conductivity type opposite to the first conductivity type and the layer having the first conductivity type, the impurity diffusion region being formed in the layer having the first conductivity type, the Zener diode being electrically connected in parallel with the electronic component; a plurality of penetration electrodes which are electrically connected to the electronic component and formed in respective holes in the semiconductor substrate, the plurality of penetration electrodes including a first penetration electrode and a second penetration electrode which penetrate the semiconductor substrate between an upper surface and a lower surface of the semiconductor substrate; the first wiring layer is formed on the upper surface of the semiconductor substrate and is electrically connected to an upper edge of the first penetration electrode, and connects the impurity diffusion region of the Zener diode to the first penetration electrode and the first electrode of the electronic component; the second wiring layer is formed on the upper surface of the semiconductor substrate and is electrically connected to an upper edge of the second penetration electrode, and connects the layer having the first conductivity type of the Zener diode to the second penetration electrode and the second electrode of the electronic component; and a protection film (208, 222) comprising a nitride film formed on the upper surface of the semiconductor substrate for protecting the impurity diffusion region at the upper surface, and an insulating oxide film formed on the inner wall of the holes in the semiconductor substrate and on the lower surface of the semiconductor substrate; wherein the first wiring layer is connected to the impurity diffusion region of the Zener diode via a first connecting portion, wherein the first connecting portion is formed in an opening in the nitride film, wherein the second wiring layer is connected to the layer having the first conductivity type of the Zener diode via a second connecting portion, wherein the second connecting portion is formed in an opening in the nitride film, and wherein the Zener diode is adapted to avoid, in use, that a voltage higher or equal to a predetermined voltage is applied to the electronic component.