The cap 13 is attached to the mouth portion 12 of the container main body for allowing the liquid substance filled in the container main body 11 of the nutrient solution container 10 to flow out. The cap is attached to the cap main body 22 and the cap main body 22. Connected via the bridge 19a, the bridge 19a is broken or deformed and pushed into the container main body 11 side so that the thin film 16 at the mouth can be pierced, and the container main body is filled with the thin film pierced. A connection holding structure that can hold the connection state between the communication member 19 that can flow the liquid material out of the nutrient solution container 10 and the connector that can be connected to the inside of the container main body by being connected to the cap. Including cap.栄養剤用容器１０の容器本体部１１に充填された液状物を流出させる容器本体部の口部１２に装着されるキャップ１３であって、キャップは、キャップ本体部２２と、キャップ本体部２２にブリッジ１９ａを介して連結され、ブリッジ１９ａが破断または変形されるとともに容器本体部１１側に押し込まれることにより口部の薄膜１６を突き破り可能とし、薄膜が突き破られた状態で容器本体部に充填された液状物を栄養剤用容器１０外へ流出させ得る連通部材１９と、キャップに接続されることにより容器本体部内と連通可能なコネクタとの接続状態を保持可能とする接続保持構造と、を含むキャップ。
