An electric working machine (11,111,211), comprising: a motor, a trigger switch, an electric-power supply unit configured to supply electric power to the motor, a control unit (23,123) configured to perform a motor control process for controlling status of the electric power supply from the electric-power supply unit to the motor, a signal processing unit (23,126) configured to perform a signal control process for sending and receiving a signal to and from the signal processing unit (23,126) and an external device, and to receive at least a stop-command signal (Sb) from the external device, wherein the control unit (23,123) is configured to stop the electric power supply to the motor in a case where the stop-command signal (Sb) is received at the signal processing unit (23,126) when the electric power supply from the electric-power supply unit to the motor is in process, the control unit (23,123) is configured to, once the signal processing unit (23, 126) receives the stop-command signal (Sb) and the control unit (23, 123) thereby stops the electric power supply to the motor, maintain a stop-state of power supply to the motor until the signal processing unit (23,126) receives a permission command signal (Sa) from the external device, and the control unit (23, 123) is configured to, once the signal processing unit (23, 126) receives the stop-command signal (Sb) and the control unit (23, 123) thereby stops the electric power supply to the motor, and subsequently the signal processing unit (23, 126) receives the permission command signal (Sa) from the external device, perform the electric power supply from the electric-power supply unit to the motor under a condition, in which the control unit (23, 123) determines that the trigger switch is in an off-state and the control unit (23, 123) subsequently determines that the trigger switch is in an on-state and the motor is not being driven. a motor, a trigger switch, an electric-power supply unit configured to supply electric power to the motor, a control unit (23,123) configured to perform a motor control process for controlling status of the electric power supply from the electric-power supply unit to the motor, a signal processing unit (23,126) configured to perform a signal control process for sending and receiving a signal to and from the signal processing unit (23,126) and an external device, and to receive at least a stop-command signal (Sb) from the external device, wherein the control unit (23,123) is configured to stop the electric power supply to the motor in a case where the stop-command signal (Sb) is received at the signal processing unit (23,126) when the electric power supply from the electric-power supply unit to the motor is in process, the control unit (23,123) is configured to, once the signal processing unit (23, 126) receives the stop-command signal (Sb) and the control unit (23, 123) thereby stops the electric power supply to the motor, maintain a stop-state of power supply to the motor until the signal processing unit (23,126) receives a permission command signal (Sa) from the external device, and the control unit (23, 123) is configured to, once the signal processing unit (23, 126) receives the stop-command signal (Sb) and the control unit (23, 123) thereby stops the electric power supply to the motor, and subsequently the signal processing unit (23, 126) receives the permission command signal (Sa) from the external device, perform the electric power supply from the electric-power supply unit to the motor under a condition, in which the control unit (23, 123) determines that the trigger switch is in an off-state and the control unit (23, 123) subsequently determines that the trigger switch is in an on-state and the motor is not being driven.