A method of processing a media file based on International Organization for Standardization, ISO, for an augmented reality service, comprising: analyzing at least one ISO-based media file including a position track and a virtual object track to be used for providing the augmented reality service; generating image data needed for reproducing an image by extracting the image data from the ISO-based media file; generating virtual object data for displaying a virtual object by extracting virtual object information included in the ISO-based media file; and synthesizing the image data and the virtual object data based on the position track and the virtual object track to structure a final image and reproducing the final image on a screen, wherein the position track comprises a marker table which stores a relative coordinate of an area in which the virtual object is displayed on the screen and additional information needed to express the virtual object, wherein the marker table defines a plurality of marker intervals on a time axis which is classified according to a characteristic which varies as the virtual object moves, wherein the marker table comprises at least one marker header box which includes a virtual marker information box indicating a reference virtual marker to be compared with a virtual marker used in each marker interval, and at least one marker group box which stores information of marker intervals included in the same marker group among the plurality of marker intervals, wherein the marker header box comprises: a related track identifier, ID, indicating a video track to be synthesized with the virtual object, a position group identifier indicating a position group to be used subsequently, and a marker group entry count indicating a number of the marker group box included in a current track. analyzing at least one ISO-based media file including a position track and a virtual object track to be used for providing the augmented reality service; generating image data needed for reproducing an image by extracting the image data from the ISO-based media file; generating virtual object data for displaying a virtual object by extracting virtual object information included in the ISO-based media file; and synthesizing the image data and the virtual object data based on the position track and the virtual object track to structure a final image and reproducing the final image on a screen, wherein the position track comprises a marker table which stores a relative coordinate of an area in which the virtual object is displayed on the screen and additional information needed to express the virtual object, wherein the marker table defines a plurality of marker intervals on a time axis which is classified according to a characteristic which varies as the virtual object moves, wherein the marker table comprises at least one marker header box which includes a virtual marker information box indicating a reference virtual marker to be compared with a virtual marker used in each marker interval, and at least one marker group box which stores information of marker intervals included in the same marker group among the plurality of marker intervals, wherein the marker header box comprises: a related track identifier, ID, indicating a video track to be synthesized with the virtual object, a position group identifier indicating a position group to be used subsequently, and a marker group entry count indicating a number of the marker group box included in a current track. a related track identifier, ID, indicating a video track to be synthesized with the virtual object, a position group identifier indicating a position group to be used subsequently, and a marker group entry count indicating a number of the marker group box included in a current track.