PURPOSE: To easily open a closure by a method wherein a part to be opened is sectioned into two parts by thin-wall parts formed on a peripheral edge of a top plate and on a line dividing the part to be opened in half, a grip piece is provided for each of the two sectioned parts, and one of the grip pieces is provided in a position radially corresponding to the other.

CONSTITUTION: A top plate 3 covering an opening of a container is provided inside a pouring cylinder 2. On the top plate 3, a part to be opened 4 is formed by a thin-wall part 4a. The pouring cylinder 2 has a protuberance 2a. A flange 5 is formed on the periphery of the base part of the pouring cylinder 2. A pour spout 1 is shaped into an approximately rectangular plane having each corner part gently circularly curved. The thin-wall part 4a is formed in the vicinity of the peripheral edge of the top plate 3, and a thin-wall part 4b is formed on the diagonal line of the top plate 3. The part to be opened 4 is divided in half by the thin-wall part 4b. A base part 6a of a pull ring 6 is erected in the vicinity of an intersection of the diagonal thin-wall part 4b and the thin-wall part 4a of the peripheral edge of the top plate. By pulling up one of the pull rings 6, the half of the part to be opened 4 is opened. By pulling up the other pull ring 6, the remaining half is opened.