We report a simple method of creating well-defined micropatterns on the surface of a flat PDMS stamp, making it suitable for microcontact printing of proteins. This method only requires a UV lamp (254 nm) and a TEM grid (as a photomask) to modify the surface of PDMS for creating desired micropatterns. By using the UV-modified stamp, it printed protein micropattern that resembles the original TEM grid can be obtained. Surprisingly, unlike the oxygen-plasma-treated PDMS, the UV-modified flat stamp is also long-lasting (>1 week). The method reported herein is very economical for microcontact printing applications because expensive silicon masters and microstructured PDMS are no longer required.