An effective thread number in the thread section which is disposed on the mouth section of the bottle is formed to be 2.2. That is, the thread section is formed such that the thread section 13 should serve effectively in the mouth section such that an interval between a start position and an end position should be 2.0 to 2.5. In the bottle can member 11 which has such a thread section, an outer diameter of the thread section which is formed on the mouth section is 28 to 38 mm. Also, the thickness of the mouth section is 0.25 to 0.4 mm. The thread section which has the effective thread number 2.0 to 2.5 is formed by eight-thread per inch pitch. By doing this, it is possible to put the cap desirably.