A method of protecting a component of a lithographic apparatus, the method including the steps of: providing a protective cover which is shaped to protect at least part of said component, the protective cover having a contact surface which is arranged to adhere to a first surface of at least part of said lithographic apparatus or said component; and bringing the protective cover into proximity with the component so as to cause the contact surface to adhere to the lithographic apparatus or said component and remain adhered without the application of external force. It is also provided a patterning device for use in a lithographic apparatus and a lithographic apparatus.