The present invention relates to a functional beverage including high hardness mineral water produced from salty underground water or deep seawater as an effective ingredient. The functional beverage of the present invention may not only impart a refreshing sensation in the mouth upon consumption, but may also effectively remove fatigue-causing substances such as lactic acid and free oxygen radicals and increase ATP production in the body, and vitalize ones lifestyle and improve exercise capacity and cognitive functions. The functional beverage of the present invention may show the effects of improving or maintaining anti-inflammatory and immune functions.
