PURPOSE: To discharge a content without residue by a method wherein for a cap consisting of a lid body and a pouring plug to be stored in the lid body, an appropriate area of the cylindrical pouring plug, being closer to a flange, is formed into a fitting part which is tightly fitted on a bottle mouth, and on the fitting part, a plurality of downward slits are formed.

CONSTITUTION: A cap which is fitted on a bottle mouth A is constituted of a lid body 1 made of a metal plate, which is fitted on the outer periphery of the bottle mouth A, ring body 7 which is fitted in the lid body 1, and a pouring plug 6 consisting of a cylindrical body 8 which is inserted in the bottle mouth A. Then, a flange part 8b at the upper end of the cylindrical body 8 and the ring body 7 are connected with a plurality of bridging parts 9. When the lid body 1 is fitted on the bottle mouth A, the bridging parts 9 are torn, and the cylindrical body 8 is fitted in the bottle mouth A. In this case, on a fitting part 8a of the cylindrical body 8, which is tightly fitted in the bottle mouth A, a guide part 8d is formed with a tapered part 8c which is tapered in on the bottom. Then, a plurality of slits 10 which open downward are formed while striding both parts 8c, 8d, to improve the pouring property.