PURPOSE: To make it possible to earth a connector and prevent it from falling off simultaneously by one process of work by integrally coupling an engaging portion for preventing the other connector from falling off by engagement with the connector during attachment of an earth portion.

CONSTITUTION: The device is so formed that an engaging portion 11 for preventing the other connector 2 from falling off by engaging with the other connector 2 during attachment of an earth portion 10 is integrally coupled thereto. The earth portion 10 is attached to an earth metal fitting 12 while the other connector 2 is connected to one connector 1, so that the shielded member 8 of a shielded cable 5 which is connected to the other connector 2, is earthed. Simultaneously, the engaging portion 11 integrally coupled to the earth portion 10 engages with other connector 2, which is thereby prevented from falling off; i.e., by the work of attaching the earth portion 10, the connector 2 can also be prevented from falling off. The connector can thus be earthed and prevented from falling off simultaneously by the one process of work.