To reduce the size of a cable inlet of an enclosure by using a single hole to pass plural cables having connectors.

A hole 56 large enough to pass the connectors 34 and plural holes 58 large enough to pass the cable 32 are provided at the cable inlet 24 on the lid 12 of an enclosure to pass and house a cable 30 with connector, together with a rubber packing 26 having slits to connect the connector holes 56 and cable holes 58. To this rubber packing 26, a large plug 66 fitting the above connector hole 56 and small plugs 68 fitting the above cable holes 58 are inserted together with a plug assembly 28 having an arm to connect the large plug 66 and the small plugs 68. The connector cables 30 are made to pass through the connector hole 56 moving the cables 32 from the hole 56 to the holes 58, and the plug assembly 28 is fitted.