To record who has effected password discrepancy with a recording unit, when a password disagreement signal is received from a password unlocking button.

When a password discrepancy signal from a password unlocking button 22 is input to a control section 28 through a reception circuit 26, a signal is sent to a recording unit driving circuit 34. Receiving the signal, the recording unit driving circuit 34 drives the recording unit 37. Simultaneously with that, the control section 28 sends a request for driving a monitor to a door telephone parent machine 36 through a monitor driving circuit 35, an image displayed on the monitor of the TV door telephone parent machine 36 by a CCD of the TV door telephone parent machine 36 is recorded.