The improved microphone with the removable connection to the phantom power supply facilitates the setting and provides elimination of the forgetful operation of switch-off, in e.g. convention center. The microphone provides both of manual and automatic operations of its indicator lamp having indication of the power supply, and has a manual switch which provides a common mode for operation of, and an automatic operation of both of its audio signal output and the indicator lamp. It also has a first circuit by which the indicator lamp automatically lights up, separately from the manual switch, in response to the connection to the power supply; and a second circuit by which the indicator lights out and the audio signal output is turned to off after the elapse of a predetermined time from the connection. The first and second circuits comprise respective integration circuits.