The invention provides a
capacitance microphone chip which comprises a substrate with a through hole, a diaphragm support layer arranged at the upper part of the substrate and corresponding to the substrate, a diaphragm covered at the upper part of the diaphragm support layer, a back
electrode support layer arranged at the upper part of the diaphragm and a back
electrode arranged at the upper part of the back
electrode support layer, wherein a circular
vein membrane which is concentric with the diaphragm is arranged in the
edge region of the diaphragm. In the
capacitance microphone chip provided by the invention, the
vein membrane and reinforcing rib structure of the invention can be used for effectively enhancing the
vibration amplitude of the diaphragm, thereby enhancing the change of the
capacitance in the
chip to further improve the sensitivity of a capacitance
microphone on the premise that the volume of the chip is not changed; the part, provided with a diaphragm reinforcing rib, in the
vein membrane on the diaphragm is basically maintained to perform
translational motion and the capacitance change rate of the microphone is improved; the problem that the local deformation of the diaphragm is overlarge is avoided; and the sensitivity and reliability of the capacitance microphone chip are improved.