Solanum tuberosum L. cv Jayoung (JY) is a potato with dark purple flesh and contains substantial amounts of polyphenols. In this study, we evaluated the therapeutic effects of S. tuberosum L. cv JY in a mouse model of Dermatophagoides farinae body (Dfb)-induced atopic dermatitis (AD). The ethanol extract of the peel of JY (EPJ) ameliorated Dfb-induced dermatitis severity, serum levels of immunoglobulin E (IgE) and thymus and activation-regulated chemokine. Histological analysis of the skin also revealed that EPJ treatment significantly decreased mast cell infiltration. The suppression of dermatitis by EPJ treatment was accompanied by a decrease in the skin levels of type 2 helper T-cell cytokines such as interleukin (IL)-4, IL-5, and IL-13. The induction of thymic stromal lymphopoietin, which leads to a systemic Th2 response, was also decreased in the skin by EPJ. Nuclear translocation of nuclear factor-κB p65 was decreased by EPJ in Dfb-induced NC/Nga mice. The protein expression of filaggrin in the AD-like skin lesions was restored by EPJ treatment. These results suggested that EPJ may be a potential therapeutic tool for the treatment of AD.