Connector with electrostatic breakdown preventing smoothing circuit and switching mechanism

An electrostatic breakdown prevention apparatus includes an electrostatic breakdown preventing smoothing circuit 4 provided for a signal line 2 on an electronic apparatus body side for smoothing a signal inputted to the signal line. A connector 3 for connection of the signal line is provided with a switching mechanism 5 for stopping the smoothing function of the electrostatic breakdown preventing smoothing circuit when the connector is connected, but restoring the smoothing function of the electrostatic breakdown preventing smoothing circuit when the connector is disconnected. The smoothing circuit may comprise a grounding line 7 connected to the signal line, a resistor 6 connected to the signal line, and a capacitor 8 interposed in the grounding line. The switch mechanism may be a reed switch.