A closure for cable connection capable of being readily assembled with fastening force of a sufficient level, rapidly accomplishing leading-out of a cable from a cable connection section and storage of the cable, and exhibiting enhanced airtightness while exhibiting increased reliability. The closure includes sleeve members and end plates. The end plates are each provided with slits which extend from cable guide holes to an outer surface of the end plate. Each cable guide hole is provided thereon with a thin-wall cap and the slit is detachably fitted therein with a rigidity holding member. An adhesive tape-like gasket is interposed between an outer periphery of the end plate and an inner surface of a sleeve so as to cover an outer end portion of the slit.