Provided are an apparatus and method for treating wafers using a supercritical fluid. The wafer treatment apparatus includes a plurality of chambers; a first supply supplying a first fluid in a supercritical state; a second supply supplying a mixture of the first fluid and a second fluid; a plurality of first and second valves; and a controller selecting a first chamber of the plurality of chambers for wafer treatment to control the open/closed state of each of the plurality of first valves so that the first fluid can be supplied only to the first chamber of the plurality of chambers and selecting a second chamber of the plurality of chambers to control the open/closed state of each of the plurality of second valves so that the mixture of the first fluid and a second fluid can be supplied only to the second chamber of the plurality of chambers. The wafer treatment method involves performing a predetermined treatment such as etching, cleaning or drying on wafers within only one of the plurality of chambers, followed by wafer treatment on the succeeding chamber, and thus allowing for sequential wafer treatment within each of the plurality of chambers.