Abstract: The present invention provides an auxiliary film comprising a body and a plurality of microstructures formed on a first surface of the body, the microstructures include a concave-convex appearance on the first surface, and the microstructures have two ends extending to the periphery of the first surface respectively. When the auxiliary film is attached to a pre-protected surface of a substrate, the microstructures and the surface of the substrate form several open air channels to increase the separation efficiency of the main body from the substrate and reduce the overall process time.