The present invention provides a therapeutic agent for psoriasis or atopic dermatitis, which comprises anti-Staphylococcus-aureus antibodies as an active ingredient. Specifically, the following is provided: a therapeutic agent for psoriasis or atopic dermatitis, which comprises, as an active ingredient, comprehensive anti-Staphylococcus-aureus surface antibodies comprising antibodies raised against entire protein molecules expressed on the surface of Staphylococcus aureus, which is produced by: (a) treating Staphylococcus aureus with a protein crosslinking/fixation reagent to fix proteins expressed on the surface of Staphylococcus aureus via intramolecular crosslinking； (b) administering, as an immunogen, Staphylococcus aureus treated with the protein crosslinking/fixation reagent for protein fixation to an animal； and (c) obtaining an antibody from the animal.
