The present invention uses a syringe (3) having a needle (33) to suck a drug housed in a drug container (2) having a lid (22) that can be pierced by the needle (33). The lid cover (1) of the medicine container (2) for preventing the medicine from leaking into the external space when performing, the insertion surface into which the needle (33) is inserted in the lid portion (22) A peripheral wall portion (10) that can be attached to the lid portion (22) so as to surround, and a top surface portion (50) that is continuous with the upper portion of the peripheral wall portion (10) and can be pierced by a needle (33)； The peripheral wall portion (10) and the top surface portion (50) are formed of an elastic material, and the peripheral wall portion (10) is attached to the lid portion (22) so that the insertion surface and the top surface portion (50) The closed surface (S1) is formed between them, and the embedded surface is not exposed to the external space. The top surface portion (50) is formed to surround the central portion (51) and the central portion (51) which are opposed to the piercing surface and into which the needle is inserted, and the central portion (51). ) And an outer peripheral portion (52) having a thickness smaller than that of the outer peripheral portion.本発明は、針（３３）を有するシリンジ（３）を用いて、針（３３）により刺通可能な蓋部（２２）を有する薬剤容器（２）内に気密に収容された薬剤の吸引を行う際に、薬剤が外部空間に漏洩するのを防止するための薬剤容器（２）の蓋カバー（１）であって、蓋部（２２）において針（３３）が刺し込まれる刺込み面を囲むように蓋部（２２）に対して取り付け可能な周壁部（１０）と、周壁部（１０）の上部に連続し、針（３３）により刺通可能な天面部（５０）とを備え、周壁部（１０）及び天面部（５０）は、弾性材料により形成され、周壁部（１０）が蓋部（２２）に対して取り付けられた状態で、刺込み面と天面部（５０）との間に閉鎖空間（Ｓ１）を形成しつつ、刺込み面が外部空間に曝されることのないように刺込み面を気密に収容するように構成され、天面部（５０）は、刺し込み面と対向し針が刺し込まれる中央部（５１）と、中央部（５１）の周囲に形成され、当該中央部（５１）よりも肉厚の薄い外周部（５２）と、を備えている。
