The present invention relates to a skin conditioner comprising the compound represented with the general formula: (wherein, the symbols are the same as those defined in the text). Examples of active ingredients of the present invention include L-arginine and ethanolamine. These active ingredients can be acquired as chemical synthesis products, or they may also be acquired in the form of natural substances. Preferable examples of natural substances include substances containing L-arginine and/or ethanolamine obtained from rice. The skin conditioner as claimed in the present invention demonstrates remarkable effectiveness as an agent for the prevention and treatment of atopic dermatitis and as a skin moisture retention agent.