To simply obtain safe and palatable mineral component dissolved water by adding carbon dioxide to drinking water and passing this water through a hardly soluble mineral componentcontaining substance to bring the same into contact therewith to dissolve a mineral component in the water and subsequently removing excessive carbon dioxide dissolved in drinking water.

The drinking water in a water tank is supplied to a carbon dioxide adding part by a liquid sending pump 7 to dissolve carbon dioxide in the drinking water and, when this carbonated water is passed through a limestone packed part 9, calcium is dissolved by the action of carbon dioxide in drinking water and this calcium dissolved water is returned to the water tank 6 by a three-way cock 10. Water in which calcium is dissolved by circulating and passing drinking water is passed through a water emitting port 11 having carbon dioxide removing function by the changeover operation of the three-way cock 10 to be supplied to a user. Carbon dioxide is supplied to the hollow parts of a hydrophobic porous hollow yarn membrane module 12 and discharged to the carbon dioxide adding part 8 as fine gas bubbles from the micropores of porous membranes to be dissolved in drinking water.