threads 217 of the main body 200a and with a radially inner cylindrical portion 224 extending downwardly from the inner surface of the cap top 222 the cylindrical portion 224 is provided with external screw threads 223 which have the same screw direction as that of the threads 217 but have a pitch larger than that of the threads 217 the cylindrical piercing member 201 as shown in fig1 a and 13b is provided on the inner surface with screw threads 225 to be engaged with the screw threads 223 of the cap 200b when the cap is applied to the main body 200a of the liquid pouring out device 200 and with a forward i e lower as viewed end 226 formed as a saw teeth like sharp piercing end inclined slightly radially inwardly the positions of the tips of the sharp piercing end 226 is shown in fig1 c the cylindrical piercing member 201 is also provided around the outer surface of the upper end with a wide ring 227 to which are formed diametrically opposed longitudinal grooves 228 to be engaged with the longitudinal ribs 219 provided on the inner surface of the main body 200a through openings 229 are formed below the ring 227 the engagement of the longitudinal ribs 219 and the longitudinal grooves 228 is made at diametrically opposite positions so that the piercing member 201 can be longitudinally moved smoothly the saw teeth shaped piercing end 226 has highest teeth at diametrically opposite positions and lowest teeth or portions at positions on a diametrical line perpendicular to the line connecting the highest teeth the operative relation of the cap 200b the piercing member 201 and.