To provide a device for switching a cable connection state, capable of reducing part of operation processes from identification of a power distribution wire generating a ground fault to its repair and restoring power supply at an early stage.

The device includes a cable connection 11 for connecting a base end of a connection cable 2 connectable to the power distribution wire W, an electricity-charge device connection 13 for connecting an electricity-charge device 4 which can apply DC current to the connection cable 2, a grounding conductor connection 12 for connecting a base end of a first grounded grounding conductor 3, and a switch 6 capable of switching an applicable state for applying DC current to the connection cable 2 by connecting between the cable connection 11 and the electricity-charge device connection 13 and a ground fault state for grounding the power distribution wire W through the connection cable 2 by connecting between the cable connection 11 and the grounding conductor connection 12.