In this report, nanopatterns consisting of an organic polymer film were fabricated using a simple detachment method. The method used a patterned ultraviolet (UV) curable poly(urethane acrylate) (PUA) as a mold and an organic polymer layer as a template material. A thin film was prepared by spin coating and then annealed below the glass transient temperature while in physical contact with the PUA mold. The polymer layer in contact with the mold was detached due to the difference in adhesion force, resulting in a well-defined nanoarray of the polymer template. Nanopatterns as small as 70 nm lines were fabricated using this approach.