A display apparatus and a display method of a display apparatus to which a 3D display film is attachable are provided. The display method according to various exemplary embodiments of the present general inventive concept includes sensing whether a 3D display film is attached to or detached from a display apparatus, automatically converting the display apparatus into a 3D mode when the 3D display film is attached to cover a display unit of the display apparatus, and automatically converting into a normal mode when the 3D display film is detached from the display apparatus.