Provided is a wireless microphone system comprising a microphone and a wireless receiver, wherein the wireless microphone system is provided with: a normal communication mode in which communication is performed by using a normal unique word (UWN) preset in both the microphone and the wireless receiver devices; a confidential setting mode in which a confidential unique word (UWX) is transmitted without being set in either of said devices; and a confidential communication mode in which communication is performed by both said devices by using the confidential unique word (UWX) set by the confidential setting mode.