PURPOSE: To automatically release the emergency stop condition of an emergency stop switch when a remote control box of a machine having a controller is separated from the controller.

CONSTITUTION: The emergency stop switch 6 inside a remote control box 5 is electrically connected to a controller 1 through an emergency stop release device 3, and the on/off command signal of the emergency stop switch 6 is transmitted to the controller 1 through a connector 4 for a switch. Between power terminals 14 and 15, a break contact 19 for releasing emergency stop of an emergency stop release device 3 is connected in series with the winding 12 of a relay 11 for communication and in parallel with an emergency stop switch 6, and the winding 18 of a relay 17 for releasing emergency stop, a connector 20 for releasing emergency stop, and a connector connection line 21 are connected in series. This connector connection line 21 is provided in a remote control box 5, and the connector 20 for releasing emergency stop is connected later than the switch connector 4, and is cut off earlier than the switch connector 4.