A lid for closing a mouth of a container, and is made of a material principally including a paper material, the lid comprising: a side wall for being fitted to the mouth of the container; and a top lid that is surrounded by the side wall , wherein the top lid includes: an inlet/outlet formation part that forms an inlet/outlet for an article stored in the container; and the inlet/outlet formation part is mounted with a sticker member , wherein the inlet/outlet formation part includes an inlet/outlet and a closing piece for closing the inlet/outlet, wherein the sticker member is joined to the closing piece , the sticker member includes one end that is mounted to the closing piece , and another end that opposes the one end , and the another end of the sticker member is mounted on a surface of the top lid in a peelable state, a first joint joined to the closing piece is formed at the one end of the sticker member , the closing piece has one end that is located away from a center of the top lid and is a free end, and another end that is located close to the center of the top lid and is a fixed end, and the closing piece is configured to be opened/closed by a hinge formed at the another end of the closing piece . a side wall for being fitted to the mouth of the container; and a top lid that is surrounded by the side wall , wherein the top lid includes: an inlet/outlet formation part that forms an inlet/outlet for an article stored in the container; and the inlet/outlet formation part is mounted with a sticker member , wherein the inlet/outlet formation part includes an inlet/outlet and a closing piece for closing the inlet/outlet, wherein the sticker member is joined to the closing piece , the sticker member includes one end that is mounted to the closing piece , and another end that opposes the one end , and the another end of the sticker member is mounted on a surface of the top lid in a peelable state, a first joint joined to the closing piece is formed at the one end of the sticker member , the closing piece has one end that is located away from a center of the top lid and is a free end, and another end that is located close to the center of the top lid and is a fixed end, and the closing piece is configured to be opened/closed by a hinge formed at the another end of the closing piece . an inlet/outlet formation part that forms an inlet/outlet for an article stored in the container; and the inlet/outlet formation part is mounted with a sticker member , wherein the inlet/outlet formation part includes an inlet/outlet and a closing piece for closing the inlet/outlet, wherein the sticker member is joined to the closing piece , the sticker member includes one end that is mounted to the closing piece , and another end that opposes the one end , and the another end of the sticker member is mounted on a surface of the top lid in a peelable state, a first joint joined to the closing piece is formed at the one end of the sticker member , the closing piece has one end that is located away from a center of the top lid and is a free end, and another end that is located close to the center of the top lid and is a fixed end, and the closing piece is configured to be opened/closed by a hinge formed at the another end of the closing piece . <EOS>