Disclosed herein is a protective film. The protective film is produced by alternate coating of a polysilazane-based polymer and a flexible polysiloxane-based polymer. The polysilazane-based polymer is cured at low temperature to form silica, thereby achieving high hardness and high light transmittance. The protective film has improved interfacial adhesion between the respective coating films, which prevents permeation of moisture and oxygen. In addition, the protective film can be easily produced by low-temperature wet processes. Also disclosed herein is an encapsulation material comprising the protective film.