To provide a closure for drop cable connection which facilitates extension construction of a drop cable.

A necessary number of lead-out cables 24 fitted with connectors 26 atop are led out of a closure body 18 fitted to a trunk cable 16 so that the connectors 26 are positioned outside the closure body 18, and the respective lead-out cables 24 and the secondary coated optical fibers of the trunk cable 16 are connected in the closure body 18. The closure body 28 is sealed in this state and the connectors 26 atop the lead-out cables 24 are covered with waterproof covers 30. When a drop cable 20 is connected, a waterproof cover 30 is removed and a connector 34 fitted to the base end of the drop cable 20 is coupled with the connector 26 atop the lead-out cable 24 to connect the drop cable 20 without opening the closure body 18.