The present invention aims to provide a pre-filled syringe coated with a resin film capable of reducing sliding resistance and preventing liquid leakage by a simple method. The present invention relates to a gasket for a pre-filled syringe, which has a sliding side surface that is coated with an inactive resin film and further cut to form a cut. The cut region is preferably between ring-shaped ribs on the sliding side surface, or in a ring-shaped rib on the sliding side surface.