Provided is a novel transdermal preparation which contains, as an active ingredient, silodosin, a salt of silodosin, tamsulosin or a salt of tamsulosin, and which is capable of maintaining a dissolved state for a long period of time and has excellent skin permeability, while exhibiting percutaneous absorption effectively and continuously. A transdermal preparation which contains: an acrylic adhesive containing an acrylic copolymer which is a copolymer of at least one (meth)acrylic acid monomer and at least one vinyl monomer, and which contains a carboxyl group； and at least one percutaneous absorption enhancer that is selected from the group consisting of oleyl alcohol, lauryl alcohol and lauromacrogol.
