A carbonic water production apparatus equipped with a carbonic acid gas dissolving apparatus 3 and a circulation pump 1 wherein water in a bath 11 is circulated by the circulation pump 1, and a carbonic acid gas is fed into the carbonic acid gas dissolving apparatus 3 to dissolve the carbonic acid gas in the water, and wherein the circulation pump 1 is a positive-displacement metering pump having a self-priming ability; a carbonic water production method using this apparatus; a carbonic water production method comprising an early step for producing a carbonic water and a concentration maintaining step for the carbonic water; a carbonic water production apparatus equipped with a control for controlling the feeding pressure of carbonic water gas so that give an intended concentration of carbonic acid gas; a carbonic water production apparatus which automatically discharges out a drain; and a carbonic water production apparatus combined with a portable foot bath.