Lid and container provided therewith

A lid for attachment to a container body that has an opening in an upper part, comprising:

• a body part that closes the opening of the container body and has an air hole for communication with the inside of the container body, and
• a flap that includes a base, a hinge that is provided on a first end of the base and connected to the body part, and a projection that is provided on a second end side of the base and fitted in the air hole so as to be capable of sealing the air hole, and is configured to be swingable around the hinge between a first position in which the projection fits in the air hole and a second position in which the air hole is open,
• wherein the body part and the flap are integrally formed from resin, and
• wherein, the projection includes a surface on a distal tip of the projection, the surface being substantially parallel to the second end side of the base, and as the flap swings from the second position to the first position, the surface on the distal tip of the projection comes into contact with a circumferential edge of the air hole on a side opposite the hinge, the projection then, while moving toward the hinge side, fits into the air hole as the flap elastically deforms in response to downward pressure.