The present invention is a lid cover (1) for a drug container (2) having a lid part (22) puncturable by a needle (33) attached to a syringe (3) and containing a drug in an airtight manner. When the drug is sucked using the syringe (3), the lid cover (1) prevents the drug from leaking to the exterior space. The lid cover (1) is provided with: a peripheral wall section (10) which can be attached to the lid part (22) so as to surround a puncture surface of the lid part (22) which is punctured by the needle (33)； and a top surface section (50) which is contiguous with an upper part of the peripheral wall section (10) and can be punctured by the needle (33). The peripheral wall section (10) and the top surface section (50) are formed by an elastic material and are configured so that when the peripheral wall section (10) is attached to the lid part (22), the puncture surface and the top surface section (50) form a closed space (S1) therebetween and the puncture surface is accommodated in such an airtight manner as not to be exposed to the exterior space. The top surface section (50) is provided with: a center portion (51) which faces the puncture surface and is punctured by the needle； and an outer peripheral portion (52) which is formed around the center portion (51) and is thinner than the center portion (51).
