a directional silicon condenser microphone having an additional back chamber is disclosed . the directional silicon condenser microphone comprises a case having a front sound hole for passing through a front sound ; a acoustic delay device for delaying a phase of a sound ; a substrate including a chamber case , a mems chip having an additional back chamber formed by the chamber case , an asic chip for operating the mems chip , a conductive pattern for bonding the substrate to the case , and a rear sound hole for passing through a rear sound ; a fixing means for fixing the case to the substrate ; and an adhesive for bonding the case and the substrate , wherein the adhesive is applied to an entirety of a bonding surface of the case and the substrate fixed by the fixing means .