The upper end of a cylinder (8) located in a mouth (3) of a bottle (2)
abuts the top plate (5b) of a seal cap (5). The cylinder (8) has formed
in the outer surface thereof a circumferential recess (10) normally
sealed by a sealing member (9). The bottle (2) contains hydrochloric acid
(second component) of a diluted concentration, while the circumferential
recess (10) in the cylinder (8) contains sodium hypochlorite as a first
component. When a user removes a stopper ring (6) and next turns the seal
cap (5) in the tightening direction, the circumferential recess (10)
moves to and below the sealing member (9) and permits the first component
to flow into the bottle (2) and mix with the second component. As a
result, sterile water of a pH level within the slightly acidic or neutral
region is produced. Then, the user can use the prepared sterile water for
sterilization by hypochlorous acid.