Method for increasing moisture content of skin surface and improving moisture-retaining function of dermis and beauty device therefor

Provided are a method for increasing the moisture content of the skin and improving the moisture-retaining function of the dermis, without generating steam or mist, to thereby improve the skin elasticity, and a beauty device for supplying moisture to the skin. A user is irradiated with positive/negative ions which are generated by using an ion-generating means (6) and carried by a low-speed air flow from a blower (7). At the same time, the concentration of the ions for irradiating the user's skin surface is elevated to a definite level or greater. Thus, the positive/negative ions react with each other to produce water which moistens the user's skin and improves the skin elasticity. When the ions supplied from the ion-generating means (6) are blown out from an outlet (61), the blowing speed is controlled at a low level while elevating the ion concentration.