The invention provides functional food and beverage that produce, through oral intake, a promotive effect on normal epidermal keratinization, and an epidermal differentiation and keratinization promoter for use in such functional food and beverage. The epidermal differentiation and keratinization promoter of the present invention contains, as an active component, fermented milk whey obtained by fermentation of milk with bacteria including lactic acid bacteria, such as Latobacillus helveticus. The functional food and beverage for promoting epidermal keratinization of the present invention contains the epidermal differentiation and keratinization promoter.