High pressure (HP) is recognized as the alternative process technology of heat treatment in food production. Although milk was the first food product to be treated with HP, the allergenicity of HP-treated milk remains to be elucidated. Thus, this study was conducted to investigate the effects of HP treatment on the alleviation of atopic dermatitis (AD) caused by milk in a mouse model. To investigate the effect of HP treatment on the alleviation of AD, Balb/c mice were fed HP-treated milk orally for 7 days following induction of AD with 1-chloro-2,4-dinitro-benzene (DNCB). Mice fed with HP-treated milk exhibited markedly lower serum IgE level than DNCB-treated mice. These results suggest that HP may be applicable as an alternative process for the development of hypoallergenic milk products.