To provide a cap capable of adjusting a flow rate without raising a cost, although, when a spout has a narrow aperture, a pull top cannot be used even if prepared, because hooking a finger on the pull top is not possible, therefore an inner plug provided with a spout capable of adjusting a flow rate is attached to a container, thus resulting in increasing the number of parts and raising a cost.

Two thin and horizontal slits 41 and 42 are cut with a part which becomes a knob 43 and an adjacent hinge 46 being left uncut, and an undercut engaged with a projection formed at a spouting cylinder 2 of a container is formed on an inner peripheral surface in a lower part of the cut of the thin and horizontal slits 41 and 42. Besides, an inner ring 30 is formed in the rear of the top 3 of a cap, the shape of the inner ring 30 is configured so that the length of the inner ring 30 in a position where the hinge 46 is located is shortened and the length of the inner ring 30 in a position opposite to the side where the hinge 46 is located is lengthened, and a spout 12 in which a notch 33 is formed is formed in a lengthened part and the amount of flowing can be adjusted between the length of the notch and a head of the spouting cylinder of the container.