A microphone includes an output controller 14 to control output from a microphone unit 10, a metal portion 20 of an outer casing of the microphone, a neon tube 24 to discharge static electricity from an external object through the metal portion 20, and an acoustic coupler 30 to control the output controller 14 through generation of sound in response to a discharge current from the neon tube 24 and detection of the sound.