To provide a bottle main body capable of easily pouring contents out of the bottle main body in spite of the fact that its recycling processing is easy and its mouth is simple in structure, and further capable of reliably preventing the contents from leaking to the bottle main body when a cap is attached to the mouth.

A mouth 3 of a bottle main body is formed into the shape of a top end-like portion 7 in which an upper edge portion of a side wall 5 of the mouth 3 is expanded outward, and a gutter-like pouring portion 6 made by cutting off a part of the side wall 5 in the peripheral direction thereof is formed in an inner face of an upper end of the side wall 5. A cap 4 has a disc-like top wall 11 whose diameter is larger than an outer diameter of the mouth 3 of the bottle main body, an inner cylinder-like outer cylindrical portion 12 extending downward from an inner circumferential edge of the top wall 11 along an outer circumferential face of the mouth 3, and a cylinder-like inner cylindrical portion 13 positioned on an inner side of the outer cylindrical portion 12 and extending from the top wall 11 along an inner circumferential face of the side wall 5 of the mouth 3, all being formed integrally. A support portion 20 is provided on the inner circumferential face of the inner cylindrical portion 13 so that the inner cylindrical portion 13, which abuts against an inner circumferential pressure contact portion 18 of the mouth 3, is not moved inwardly, and a liquid leakage- preventing packing 19 is provided at an upper end of the inner face of the outer cylindrical portion 12 so that an upper edge of the top end of the mouth 3 abuts against the packing 19.